New chapter! Just before the month ends. Now, I'll be honest with y'all, this chapter had me brainstorming for months while I was gaming, especially the ending scenes. Sorry about that. This chapter is a long ride, so I hope you guys sit tight for this and have fun reading.

*Update: Clayface's backstory in more detail.*

Chapter Eight:

The X Growing X Battle

Robin touched down on the rooftops, maintaining his stature through the shocks from landing. He loomed towards the ledge, roaming his eyes along the streets below him. Disappointment reigned after viewing the deserted pedways.

Robin solemnly looked up at the cloudy, smog-thick painting that decorated the sky. It was the afternoon when he refused Batman's order in favor of looking for the missing girl. Robin had been too narrowly focused on the task to notice that the sun had long since drifted past the horizon. Patrol hours would be the usual routine tonight if he didn't decide to be stubborn. And now, he was sure he wouldn't be able to follow the schedule tonight.

Robin sighed. Bruce was going to give him the scolding of a lifetime.

A dull strain tingled his leg muscles. Robin ignored the burning in his muscles, which longed for a rest after scouring the streets for hours. Of course, after endlessly searching for Annie for over six hours, it would eventually take a toll.

He squinted at the shadows around him before blinking at a certain area ahead of him. Had Robin wandered so far into Old Gotham that he was beginning to tread into the Narrows? These structures seemed even more ancient than anywhere else on this side of the city, towering alone in the midst of what was one of the oldest settlements of Gotham, with their exteriors aging and worsening as the years passed. Through the darkness, Robin could make out the many window openings nailed shut with wooden planks.

A thought came to mind, spurring Robin to shoot his grapple hook and swing overhead the cracked roads. His face remained unflinching through the chilly wind. He lowered his altitude via his gadget until his feet touched the surface. Robin had to go on with caution now. While this place had the poorest population in Gotham, criminal activity was frequent in these parts.

Light from the corner of his eye ushered Robin to peer to his left through an alley to see a group of figures huddling around a tin can with a blazing fire. Two of the larger ones were a man and a woman, and the two smaller ones were girls sitting between them—a family. None of the children looked to match Annie's identity.

Robin turned away and continued his trek. His heart silently went out to that family. He reminded himself to tell Bruce if he could help them from their poverty.

Eventually, Robin came across the runaway center that Bruce presumed was where Annie belonged. It would make sense. Right? Robin frowned at the state of the building. Unlike most of the dying buildings in the Narrows, it lacked a roof. Its condition was nothing short of a wreckage.

Robin took a deep breath before he passed under the overhanging archway. He advanced into the room and peered through the blackness to see several children of various ages snuggling close on a bed. They were in a deep sleep, oblivious to the presence of their visitor. Robin stared with a grim gaze at the children living under such conditions. Sadly, he did not find any resemblance to Annie among the girls.

Dejection overcame him. Robin knew Bruce had been right the moment he stubbornly defied his orders. As he thought about Bruce's wishes, he regretted not honoring them. If not for Bruce, this place might have been his home. Robin vehemently shook his head. He was thinking unhappy thoughts, and this place's atmosphere didn't do any favors. Perhaps it was time he returned to the manor.

After one last sorrowful glance at the sleeping kids, Robin turned away and silently departed.

Killua lightly touched down on the stone-cold surface, his eyes fastly darting in every direction before he slightly relaxed. He looked ahead to see the same retail store where he fought that clay monster the night before. Killua peered through the building's front windows, and his icy eyes were met by darkness filling the interior. The only sound he heard was the distant wail of vehicles in their rush that blended into the ambient atmosphere.

This store was completely dead, thanks to that ruckus the monster caused. Killua's gaze detached from the window and scoured the parking lot. His sight faintly took note of the yellow lines the cops like to wrap around every perimeter where any disturbance happened. But he wasn't here to investigate the scene.

Now to that entrance to the sewer. Killua thought.

Killua advanced to the area on the right of the store itself. He took a peek at the side exterior and saw the same gaping hole, a collateral result of the fight against the clay monster. Police crossing lines barricaded from every corner of that hole. He faced forward and saw the manhole not far off. The traces of mud were barely visible to his eyes after a whole day had passed.

Killua slickly slipped through the narrow space, and he found himself freefalling down the vertical tunnel. The tippy ends of his shoes contacted the concrete, and a wet muck smell almost instantly bombarded his nose. Ahead of him was a one-way tunnel. He unwedged his hand from his pockets and electricity sparked to life on his right hand. Crackling blue light flashed through the tunnel. Killua cooly began his trek.

He hoped these mud tracks would take him far enough in the right direction to narrow down the monster's general location. Killua doubted finding him would be simple. Logically, the muddy freak should be lying low after the incident. He recalled that shape-shifting ability he witnessed in the fight.

Could he change his entire form to look like anything? So, if that were true, then the monster would be impossible to find if he didn't want to be found.

That was the only impressive power he possessed as far as Killua knew. Every other attack that monster threw was slow. Yet, he was the strongest opponent he came across. But fighting him was still a bore. Once he'd tracked him down, a selfish part of Killua hoped that he had unlocked the monster's Nen nodes for the possibility of a more thrilling fight.

Once a certain amount of time passed, Killua halted, and uncertainty began to loom. Ahead of him were three routes; one continued on straight, one sharp left, and a right. The waterways formed a plus in the junction. Squinting his eyes, Killua looked to the brick floor to catch the faint trail. With a nod, Killua followed the left route.

This tunnel seemed like an endless trek to follow. Killua figured he would take the nearest exit to the surface once the mud trail inevitably ended, and that would be the area in the city he would investigate.

It had been long since Robin had left the Narrows at Old Gotham. He drifted along the sidewalk as he swayed his sight around the block, observing the heavy public activity in the area. The cityscapes in this part of Gotham contrasted with the Narrows'. It was almost as if this was a completely different city.

Robin gazed in slight awe at the towering complex of the Gala Premier across the wide road. A crowd of people in formal wear hung out at the entrance near rows of klieg. The devices danced their rays toward the sky above the street, granting an extravagant view to the passersby.

Not allowing the scene to take too much of his attention, Robin continued his walk, remaining vigilant of Annie's whereabouts.

"You shouldn't be trying so hard to help me." A soft, familiar voice spoke somewhere behind him.

Robin almost jumped at the sudden voice. He turned his body, and out from the alley stepped out Annie. A sense of irony settled in his thoughts. It took Robin the entire evening to search for Annie, only for her to find him.

Annie wore her red, light-open sweater, exposing her yellow shirt underneath. She looked at him timidly. "He'll hurt you too," She continued.

"Maybe so," Robin trailed his words as he took a few steps closer. "But I'm fully prepared to handle him the next time."

"What makes you so sure? You've seen what he can do. That Killua…"

"He's not what you saw him as," he spoke before shaking his head, "It's a lot to explain who he is, but I've dealt with others like him. I have no idea why he's after you, but I'll do all I can to bring him in. To keep people like you safe."

Annie couldn't help but stretch a smile at his words. She reached forward and lightly took hold of his arm. "So you actually do care. You're the only person I can remember who ever did."

Robin wordlessly stared at her, not knowing how to respond to her words, especially from those eyes of hers. His mouth gaped a bit as soon as he noticed her leaning forward. A silent gasp echoed in his throat as the distance between their faces grew little. Annie gifted him a peck on his cheek.

A subtle blush plastered his face. Rubbing at his nape, Robin couldn't hold in a sheepish giggle. "Y-yeah, but you don't remember anything."

Annie turned away briefly with a close-eyed smile, letting out a chuckle that was a jingle to Robin's ears as he watched her turn to him with a bright expression. After her gaze lingered on the costumed boy, Annie shifted her focus to the shining rays that spawned from the klieg lights at the gala. A sense of deja vu began to bloom the longer her eyes followed the lights. It was like they were taunting her, daring her to dive into the depths of her mind.

Robin couldn't help but be confused, almost worried by her hypnotized expression. "What is it?"

Her eyes remained locked onto the illuminating beams. "Those lights… it's familiar."

"Good," Robin said. "Try to remember."

Annie looked down, and her face oozed with hesitance. "I've seen one like this before." She said. She shut her eyes, hoping the sight before her could allow her to paint a mental image through her blurry memories. "I was… walking toward it. It was dark, and the ground was uneven. But the light was higher! It was on top of a tower or something."

The answer to her description instantly came to Robin's mind. That was easy enough to solve. He shot her an assuring grin. "I know which place you're thinking about." He said with an etch of enthusiasm.

He stretched out his arm invitingly. "Hold onto me. I hope you won't mind the lift."

Annie gaped at the offer before her. A smile grew from ear to ear, confident she could trust in him. She gratefully nodded with acceptance, and a tiny "Mhm" escaped her lips.

Killua slid open the flat metal seal of the sewer entrance and hopped out into the open. He immediately disappeared in a blink to the nearest cover. His eyes scurried across the zone for unwanted occupants. Once he was sure no one spotted him, Killua rested his back against the stone slab wall behind him. A deep sigh hollowed out.

As expected, his search hadn't progressed well after pursuing the trail in the sewer.

That clay monster could be anywhere in this city for all he knew. A full day passed, so it was realistic to believe that his target had traveled far and wide since then. At this point, Killua hoped the people of this world did not possess aura nodes in their body structure.

That foul, murky smell still plagued his nostrils, which further rotted his mood. Killua was sure the stench stuck to his entire body from his traverse in the underground tunnels. He would have to keep in mind to shop for new clothes. He still possessed the stolen money he intended to pay for his sweets from last night. Maybe luck was on his side after all? His sarcastic thoughts whispered.

It ironically brought Killua back to the days he worked as a professional assassin in the Zoldyck name. It all came back full circle after all the attempts to cut off reminders. Maybe he'd never be able to achieve a childhood life.

Cracking his spinal and neck joints as he stuffed his hands into his pockets, Killua shot upwards. He sprang against the walls with force, speedily ascending in a zigzag rhythm. As he hovered high in midair, his eyes outlined the city's skyline as it came into view. They darted pointedly along the rooftops before him, grasping for whatever signs he could find toward his target.

A floating speck in the distance alerted Killua's attention in an instant. He squinted his eyes, the nightly atmosphere making it troubling to distinguish the figure. Or were they figures?

Before he had more time to observe it, a rush blew against him as the rooftops surged closer. Killua landed in a crouch on the roof. Intrigued by the sudden turn-up, he sped forward toward its route. The ex-assassin seamlessly bounded the roofs, and his speed handily shortened the distance. In no time, he slowed down to a comfortable pace once he reached a safe distance.

It's that kid! Killua thought. His mind running high for conclusions.

Killua would be lying if he said he wasn't slightly shocked to see that red-clad kid, the person Killua identified as the kid he bumped into at the library. He narrowed his eyes as he caught a second figure clinging to the masked boy as he continued to sling. He could tell it was a girl based on the distant features. What in the world was he doing?

Killua began to contemplate what course of action he should take. The sight of him compelled him to trail behind from a distance and judge the situation before he made any move. The clay monster he was after was likely enemies with the bat, and the kid does work for him. As Killua had no other leads to work with, this was the closest to a lead he had.

Killua looked past them in their path. The roads ahead were becoming dark, buildings were growing more scarce, and Killua could seldom make out a lighthouse silhouette. The kid was taking her somewhere, but why was he heading toward the outskirts? While this wasn't an obvious lead to the clay monster, not everything was the way it appeared.

Killua halted his trek and then watched the boy in red steadily descend to the ground once there were no high points to swing by. Killua patiently waited as he watched the boy settle the girl on her feet. Once the pair ahead of him covered some distance, Killua hopped off the roof and quickly hid behind a tree. He was even more curious as he saw the boy lead the girl off the road like he was taking her to show something.

Could this be a lead, or am I wasting my time here? Killua thought as he silently stalked their trail. If this did turn out to be a sight-seeing date Killua walked into, that would be embarrassing.

The scent of moisture with a salty touch wafted into Robin's nostrils as the tide's music played. It took more time than he preferred, but they finally made it. Ahead of him stood the lone tower on a cliff peak over the seaside; its light continued its spin, touching long distances as it pierced against the fog looming over the ocean.

Robin faced Annie, whose expression radiated with insight. "You remember anything more?" he said.

"This all feels familiar," she stated. Annie walked ahead of him, studying the surroundings. It was coming back. "I've been here before…"

Her eyes found a rocky hill. She didn't know what it was on the other side, but she felt compelled to see it like her memories were calling her back. Annie rushed forward and scaled the rough edges. She balanced herself once she stood on the hill's narrow top. Her eyes widened at the place. She gazed at the enormity of the industry establishment on a cliff across the bay. The lonely factory lay abandoned with its tunnel-like tubes overreaching the coast as it wallowed in the darkness.

Her mouth gaped at the sight, almost enthusiastically. "There, that's it! Those pipes! I remember!" Annie exclaimed.

Robin worried for her as she hurried down the hill. "Hey, you gotta slow down. One misstep will make you fall," he warned. Whether she comprehended his words or not, she didn't show. He drew a deep breath, having no choice but to follow closely behind.

Unbeknownst to them, their stalker prowled not far behind.

Bruce leaned against the chair, his eyes locked on Bat-Computer. He wore his Kevlar batsuit with his cowl free off his head. As he typed for results, he contemplated the connection between Clayface and the girl and why she was his target. Was there something missing?

The time Bruce recalled when Clayface had ever targeted anyone was out of vengeance when he began life as a criminal. A man named Roland Dagget had been his very first target, the man who ruthlessly distributed clay-like substances produced specifically to alter anyone's facial features. It was why he became who he was in the present.

Bruce's face hardened as a particular memory came to mind. Basil Karlo's face had been disfigured after a car accident beyond recognition, which was why he came to take those face-altering drugs in a desperate attempt to save his acting career. Bruce remembered that night all those years ago when he visited Karlo in his hospital bed after finding out his connections with those illegal products and gave him two choices:

To work with the District Attorney at the time, Harvey Dent, to become something more, or accept to become what he believed how society perceived him as - a monster.

Bruce closed his eyes at the outcome that had led to.

The second target, Bruce could guess, was out of bad blood when he was an actor. Karlo murdered an entire cast of actors, intending to end his list by finishing off the one who replaced him for a movie's star role. He now usually robbed banks and stores and would randomly choose to kill his targets on his killing sprees.

"Hard at work?" A voice called behind him. Bruce strained his neck to look over his shoulder and saw Diana standing beside him, crossing her arms as she gazed at the screen. She adorned a more casual set of clothes.

"Tim mentioned Clayface had been targeting a girl. I'm looking to find out if there's a connection between them. I've been here all day ever since." Bruce answered before he refocused on the computer.

Diana flinched with worry. "By the gods, is she alright?"

"She appears so, but something doesn't seem right about her. I can't put my finger on why that is," Bruce replied as he grasped his chin in thought.

His words concerned her. As if there was more to this child. "And what of Tim?"

"He's near the lighthouse, just north of Millar Harbor. I have my eye on him." He replied matter-of-factly.

"Is there anything I can do to help?" Diana asked, worried for the girl.

"We can handle this. Besides, I don't think Clayface is the right opponent for you to face."

Diana raised an eyebrow as she pressed her palms onto her hips. "And why is that? Are you saying I'm not capable enough to face him?"

Bruce shook his head, "It's not you. It's just that you fighting Clayface could have…" he paused. "Destructive results."

Diana sighed, taking Bruce's vague response to heart. "Well, okay. But if I see that you're in a situation when you can't handle him, I'm intervening whether you want me to or not, y'know." She remarked.

Bruce subtly nodded as he typed, "Noted," he said. She could just feel his smirk off his words.

Diana sighed again with endearment as she watched him focus on his work. Stubborn, as always, was Bruce. He was capable and was well within her respect as a warrior. Still, Clayface was a dangerous foe based on his destructive feats in the news articles she read. He was simply an abomination; that was one defining word for him in her mind. And it would seem safer if she teamed with Bruce to subdue him as an approach.

Still, that was one reason she admired him, willingly standing against enemies much more powerful than him and would often come out as the victor.

Tim frowned as he and Annie made their way through the tunnel. The tell itself was a massive pipe, likely made to dump waste. He could tell from the subtle putrid in the air. It was also cold enough to raise his goosebumps. Adding more to his dislike for this place, it gave him the spooks.

"I don't like this. If this is the place where you lost your memories, then we could walk into serious trouble." Robin said, turning to Annie.

"I have to know, Robin." She eyed him with a smile. "Besides, it won't be like last time. You're here to protect me." She finished with a wink.

Unfortunately, trouble had been before them all along in the unseeable black void. Robin loudly gasped when his foot met with hollow air, along with Annie's. Gravity pulled them down the pitch-black pit, and Annie's scream overtook his ears. He began to act despite the franticity. He secured the helpless Annie under his arm, hoisted his grapple gun from his utility belt, and fired the hook upwards, hoping the hook would be able to reach any ceiling.

Robin's blood ran cold when the hook had yet to secure itself against anything solid. It was dark; he couldn't tell how close the bottom of the pit was. Robin almost popped his eyes out of his domino mask as their fall took a very sharp stop, and then relief began to settle. The grapple hauled the pair steadily to the surface, shortly making contact with their feet.

He frowned at the sound of Annie's quivering breaths since the drop. He grabbed her shoulders. "Are you okay?"

Annie took a second as she breathed, pressing her palm against where her heart should be. "Y-yeah…" She answered breathlessly.

Robin looked in both directions in the narrow tunnel. "The only way to proceed is going forward," he said.

Giving her a soft smile, he reached over and gently grasped her hand and continued their treacherous journey through the abandoned tunnel. Annie frowned ahead at that same eerie feeling glowing ahead from the confines of the darkness. It was him. She could just feel that awful piercing-predatory gaze lock on her. Almost tauntingly.

"It's him." Her voice was low, barely able to contain her quiver.

Robin glared toward the path ahead as he sidestepped protectively in front of Annie. His teeth clashed against each other as the air weighed heavy with tension. He picked up a series of footsteps from the dark. Initially, one would have to keep silent for them to be detected, gradually growing louder.

Robin made out the familiar shape of his foe, very much sharing the same appearance as a particular new visitor in Gotham. White lenses clashed with the mock blue irises of the imposter, who bore a cold glare. The culprit's eyes shifted to stare at the girl hiding behind the Boy Wonder, who recoiled in fright at his gaze.

The menace sneered. "After all the trouble you put me through, you've finally come back to me."

Robin's veins burned at his boastful tone. Who did he think he was? Annie has had a terrifying few days, constantly looking over her shoulder because of him stalking her; all Clayface was concerned about was that she brought him trouble. Of course, how could an animal like Clayface feel anything for his victims?

"What do you even want with her anyway? She didn't do anything to you!" The words that reflected his thoughts on the matter rolled off Robin's tongue. Clayface's steps paused in response, and the man made of clay shot Robin a stare that would make anyone's blood run cold.

"What do I want with her?" Clayface repeated before a bloodthirsty grin slowly grew through Killua's face. "Let's just say… I'm her father, and she's coming home."

Silence fell in the tunnel, with Robin's face dropping to a dumbfounded expression. Clayface felt a pitch of satisfaction at the looks he received.

Robin thought he didn't hear him right. "H-her father?" He muttered to himself. He snapped his sight to Annie questioningly, only to see a blank look from the girl. He found it strange not being able to decipher what went on in her mind.

"Yes, now give her to me!" Clayface roared, his pale arm gigantified into a massive muddy hand and shot it forward to snatch the cowering girl.

Robin reacted in time, grasping Annie's wrist and pulling them aside from Clayface's mucky grasp. Robin and Annie narrowly dodged a second grab from Clayface's opposite arm and rushed past him.

"Come on!" Robin called out.

Clayface growled, watching them run ahead of him through his heated gaze. His shoulder bubbled, and a surge of clay sprouted out. It loomed over the pair, solidified to be rock-hard, and mock steel bars spiked down before them, barricading their path.

Hearing a yelp from Annie, Robin growled at the barrier. He tightly clenched his fist and swiped the clay with a grunt, and the bars shattered and returned to their muddy material as they flowed in the air. Robin rushed forward, grabbing Annie's hand.

Annie glanced at her outstretched arm splattered by the particles as she ran in tow.

Retracting his extra appendage into his body, Clayface hardened his arm and stretched it forward as it reshaped into a mass sphere of bricks. The pillar bulldozed its way to its targets, intending to crush Robin and swallow the girl. The two looked over their shoulder alarmingly at the mass. Robin glared ahead with determination and worked his legs faster in their rapid rhythm. Annie stumbled briefly, Robin's grip on her hand preventing her from tripping over.

They took a sharp right in the tunnel shortly before a massive crash echoed behind them. The tunnels shook from the collision, and Robin dreaded the place would collapse. He looked over his shoulder and was relieved to see Annie hold herself well.

Robin continued charging, spotting a circular vent door blocking the route ahead. He gritted his teeth, maintained his sprint, and drilled his body through the rail-like barrier. Regaining his senses, Robin noted that he had entered a large chamber deep within the factory.

He turned to Annie and frowned at the predicament she was in. It seemed as if Annie was trying to focus on the present, but her aimless stare betrayed her. He caught her occasionally eyeing the brown splatters on her arm.

"You okay?" Robin softly asked.

Annie's eyes snapped at him in surprise, followed by a quick nod. "Y-yeah..."

Their attention was drawn by a loud thump, and to their horror, Clayface stood menacingly outside the tunnel pipe.

"No more games!" Clayface proclaimed. "Just hand her over to me, and we won't-" A figure swooped in before anyone could react and delivered a solid kick to his head so hard that Clayface's eyes popped open from the impact. Clayface launched to the far side of the industrial room, and his body hit the metallic wall in a splat.

Robin gasped in a breath as his eyes slowly turned to the newly arrived visitor, standing over Clayface's position. The silver-haired boy locked his cold eyes on the brown substance painting the wall. It was Killua, without any doubt in Robin's mind. A cold sweat trickled down his forehead when Killua's sharp blue eyes caught his gaze.

Killua felt a hint of satisfaction from observing Robin's look, not minding the girl hiding behind him. Returning his focus to the enemy before him, Killua watched Clayface merge himself across him in a kneeled position.

Clayface barred his uneven teeth, rage pumping through every grain of clay within him. "You…" He whispered. "How did you find this place?"

Killua raised an eyebrow tauntingly.

"Not answering huh!? Just why couldn't you wait for your role to come!?" Clayface exclaimed, slamming his massive fist against the floor.

Robin flinched at the drastic change in Clayface's tone. Had Killua gotten even the likes of Clayface so riled up? He checked up on Annie, whose expression continued to drift. He glanced at the standoff of Killua against Clayface. He figured he should guide Annie to a place from this showdown where she could collect her thoughts.

"Let's go," Robin said, earning a lazy nod from Annie. He rushed away with Annie close behind.

Clayface's eyes widened, specifically at his fleeing target. It was getting away! Not during such a perfect opportunity to get it back! He reached his bulky arm toward it. "Don't you-!"

A shattering punch from Killua driveled into his abdomen, not unlike that punch that forced Clayface into a sputtering mess at that store. Clayface's jaw gaped widely from the impact as a throaty groan escaped him. Killua — shrouded in Ren — leaped up and struck a heavy uppercut against Clayface's broad chin. Timed slowed for Killua as he hovered above the clay monster's body as it arched backward from his strike. Killua gracefully twirled around and slammed a kick against his foe's cheek.

Clayface flew once more. His body hit and bounced against the floor in his helpless flight before colliding against the wall with a loud ring, and he fell into a heap on the floor. His mass caved a dent into the interior wall; a couple of huffs emitted from the villain after rejuvenating his missing parts.

Clayface looked up and couldn't help but widen his eyes at the sight of the silver-white-haired boy gazing down at him through his dark eyes.

"Your fight's with me, scumbag," Killua uttered, his low voice devoid of emotion.

After dashing through the deserted production area, Robin took hold of Annie and ascended to a catwalk with his grapple gun. Robin crouched under the railing as he released a breath, his arm balancing on his propped-up knee as he focused on the exchange.

Annie's eyes glued to the brown substances on her hand. Her thoughts continued to swirl around this Clayface figure. His voice rang in her mind. Suddenly, the brown goo slowly sank into her skin, and her eyes widened with a gasp. And everything crashed down at once after that moment.

Robin turned to his self-admitted crush, who crouched beside him. "How are you…" His voice trailed off.

Annie's bangs shadowed her eyes, her hand held out. "I understand everything now," She muttered heavily.

Robin perked at her words. "Really?" He couldn't help but smile. "That's good to hear! But tell me, what's your connection to Clayface?"

Silence lingered. Annie extended her mud-splattered hand in display for Robin to witness. "I am Clayface…" She said motionlessly.

Robin went agape as the skin of Annie's hand absorbed the small crumbs, and a mushy sound emerged through the motions. Robin looked up to her with a look of disbelief. If there was one thing Robin was at his most efficient, it was his sharp observation, but even this fact didn't cross his detective mind.

"Woah…" He whispered in awe.

But thinking back to Clayface's words, referring to himself as her 'father', made so much sense now.

But how? Unless. Robin thought, internally organizing for answers.

"You're his scout," Robin concluded.

Annie nodded, thoroughly impressed with his quick reasoning. "That's right." She looked down with hesitance before steeling herself. "I'll tell you what I remember. It started when Clayface had washed out to sea after he lost his battle against The Batman. He couldn't hold his form anymore for the past two years. He drifted near the pipes, and then something in the chemicals made him whole again. He didn't regain his strength yet and found himself lost…" She trailed off.

"So he created me and sent me off to find out if it was safe. I was supposed to look around and come back. But when I walked away from him, I think that's when I lost my memories." She said, a somber expression overtaking her. "And now he wants to take me back."

Robin gently grasped her shoulders. "Clayface is occupied with Killua right now; this is your chance to get out of here."

"And what are you trying to help? Even after hearing everything I said," she softly spoke. She cast Robin with a gaze that stabbed his heart. "Can't you see? I'm not real."

"Yes, you are…" Robin replied.

Killua continued to study his target for signs of aura, and a tinge of relief washed over like a wave. It's been a full day, and he should've long had his aura leak out and would've passed out from exhaustion from his inability to contain it. So, he doesn't have aura nodes. He thought.

Well, that made things simpler.

Clayface snarled at the pale superhuman in front of him. It still pissed him off the amount of pain he could feel from his strikes. What kind of freak accident did this kid go through to get this kind of strength? Did he inject himself with some type of strength serum? The only metahumans in this stinking world that could physically hurt him were Speedsters, Amazons, and aliens with god-like strength like Kryptonians.

But is he really at the same level as those guys? Clayface thought as shadowed figures representing said individuals materialized in his mental frame. He shoved those thoughts aside as he continued to breathe heavily. It didn't matter. Clayface came fully prepared for this role, even after this twist of him showing up. He hated having to resort to this straining method, but it was the only way to kill this brat.

Clayface sneered, "You weren't even part of Gotham's script two months ago and beyond. Did you think you could just come up in this city and hang high on the stage?" He asked challengingly.

Clayface received silence and a blunt glare from Killua, further angering the former actor. How he wished to knock that cocky look out of his face. Clayface tensed his stance, "I'm ready for you now! Your only role on this stage is to die!"

Killua was thoroughly bored listening to the gibberish this giant was spouting. It made his ears ache. He should remind himself to clean them after he returns to his hideout. Killua sharpened his eyes once Clayface's entire form began to gurgle. Bubbles popped, and Clayface's mass bulked to the point of veins throbbing. A vicious, primal roar resonated from the clay monster as if he was forcing every ounce of strain within him.

A gawked expression erased Killia's calculating gaze. He could tell the surging power from the gradually increasing mass of his enemy. "His strength…" he muttered. "It's skyrocketing!"

"AAAAUUUUUUUUUUGGGGGGHHHHHHHHH!" Clayface bellowed. His shoulder mass became broader, and his arms pumped with power. His height rose until he loomed over the factory machines. The two bystanders gawked at the development as they hid in the distance.

Streams of smoke seeped from several spots of Clayface's frame. The floor cracked under the escalating pressure, and soon, a webbed fissure outspread with Clayface at the center. Killua's eyes hardened at the surroundings. Even the environment was being affected by Clayface's desperate grasp for power.

Killua didn't care how strong Clayface could become, but this could cause a disturbance to warrant unwanted attention from the outside. He had to stop this. Killua sped forward and delivered an instant blow to the monster's jaw, forcing Clayface to recoil. An attack devastating enough to bring Clayface into a helpless heap had he remained in his previous state.

Clayface's eyes snapped open; he lunged forward. Killua crossed his arms in front of him, and a blunt headbutt pounded his limbs, shooting Killua to bounce against the floor until he recovered with a flip. The soles of Killua's sneakers scrapped the floor until his sliding ceased at a distance.

Killua gritted his teeth after regaining his senses. Shock coarse through him at the fact that strike alone had stung through his defenses. Clayface was more dangerous than Killua had given him credit for. Killua could see it now. This monster's raw power eclipsed even the likes of his father's physical prowess.

A freak like this could trample anyone who did not possess the ability to wield Nen. Killua couldn't believe he had to turn his power up a notch against a non-Nen user at his current level. But Killua couldn't deny this other part of himself.

Killua had to admit he was excited for a thrilling battle. This turn of events had gotten interesting.

Clayface sneered again, which spurred a snort out of Killua. "How's it like now that I can even the playing field?" He mocked. Killua could only respond with a grunt. "Don't like it?! Well, that's what happens when you cross me! The Ultimate Clayface!"

Clayface morphed his arm into a hammer large enough to presume it could level the whole chamber. "Encore!" He roared, prolonging his call, and brought it down to Killua's position.

Killua hopped out of its radius and tensed his eyes at the large, funnel-shaped pillar of dust summoned by the attack. The vibrations pulsed across the room. Killua sped a couple of bounds sideward, spawning a multitude of blurry figures of himself. Each copy mimicked the actions of the original, constantly walking a distance from Clayface in sync.

"Rhythm Echo."

Clayface balled his hand. "He can clone himself, too?" He questioned quietly at first glance, "No, that's not it. These must be illusions."

A sawblade replaced his opposite arm before swiping its jagged ridges through the transparent images, each figure blurring out of sight as it connected. Clayface withdrew his arm and spun his body around to face all angles. A glowing blue light from underneath his vision alerted his notice, and he looked down just in time for Killua to press his electrical palms on his body.

Killua poured twice the intensity behind this Lightning Palm, dwarfing the one he effectuated at the store. Killua looked up to see Clayface about to crash knuckles upon him.

"I said that won't work on me!" Clayface shouted.

Killua narrowly jumped above the destructive punch, rolled midair, and hammered an axe kick onto Clayface's head; a shockwave of aura erupted below Killua's foot. Killua then launched himself to a bird's eye view above Clayface.

"Try this on for size…" Killua spoke under his breath, his index pointing upwards. His fingertip flickering for a moment, it became a galvanizing orb. "Thunderbolt!"

Following the foreign cry, a brisking streak discharged from Killua's fingertip, depicting a vertical crack in the air. Clayface bit his teeth, snarling in pain from the watts. Parts of his body gurgled as it broiled under the electric currents.

The lightning bolt disappeared in a flash, and Killua descended, allowing gravity to drop him to his opponent. He somersaulted midair, brought his legs together, and stomped his feet onto the brute's nape. A resounding shockwave coursed to the floor, and an awe-inspiring bowl of debris surrounded them.

Clayface dropped his jaw as his neck hung down. He craned his neck to catch a glimpse of that pale brat standing on the base of his shoulders. Clayface spun around with an attempted surprise swipe with an axe, only to hit space. He quickly turned to scan the makeshift battlefield, eyes burning with rage.

A grunt of frustration escaped him. He's still too fast! Clayface thought.

Clayface's arm flattened into a broad, diamond-shaped shield. A woosh caught his senses from his right, and he immediately snapped his sight; nothing. His mudded face was smashed by a punch from nowhere, forcing him to take a short flight away. His back slid against the flooring before he straightened into a knelt position.

Killua fazed forward, causing Clayface to gape helplessly before a knee drove against his facials, comically caving his features. Clayface stumbled, desperately trying to maintain his footing before a gigantic slash rendered his body in half. Clayface's expression froze with agony as his upper half splattered to the surface near his feet.

Killua sighed after he turned around to see the messy sight, still disappointed by the pace of this fight. Yes, this clay monster became strong, his physical strength surpassing even that of Neferpitou's, a chimera ant royal guard. But that power he attained was worthless if he couldn't land a single hit to save his life. Killua had yet to cut halfway loose.

What a waste, honestly. Killua thought. It was especially true after witnessing how the clay monster could pump himself with power— an impressive ability.

Clayface didn't take long to remold his body. One would see the hot steam rise from his head. His teeth bore so hard that Killua could hear them grazing. "I'LL KILL YOU, YOU SON OF A-"

Clayface's vocal tantrum was cut off by a series of punches and kicks, with each leaving an imprint on his torso before one final stiff punch impaled his face.

Robin had been silently witnessing the clash in disbelief. A battle of this intensity was well beyond his league. While this may be the first time he ever encountered Clayface, Robin learned of Clayface's abilities when Bruce took him to read through every profile on Gotham's Rogues Gallery. Clayface was every bit the absolute monster described by his words, and nothing was exaggerated.

And yet, Killua is still beating him senseless.

He turned to see Annie hugging her knees with her face obscured between them. She had tried insisting him to abandon her amidst this chaos. His heart soared for her at the thought. She didn't consider herself human because she was practically a piece of Clayface. But how could some lifeless fragment manifest a personality with Clayface having no control over it?

It couldn't.

It was why Annie was as much a living, breathing being as any other person. She was alive, her own entity. Seeing the lack of self-worth didn't belong on someone so pretty.

He looked down at his commlink that hung from his utility belt. He knew calling Bruce to come over would do a job well done, with Wonder Woman tagging along since Killua was present. It would be killing two birds with one stone. This nightmare would end, and Annie would be free. Hesitance gnawed at him, but he shook it off and began to inch his hand to the device.

Robin sighed, not having the will to break his hesitance. He knew why, and it was because of these circumstances. Robin couldn't believe he ended up owing Killua after taking Clayface off of Annie and his backs.

He returned his focus to the clash. Clayface was helpless under the receiving end of Killua's barrage of blows. "Killua does look like he has the advantage," Robin commented quietly before squinting his eyes. "It looks like he's not pulling punches. He better end this fast, or else…"

Killua struck Clayface with a hard kick, cartwheeling the brute to bump his head against the hard surface, forming a crater on the floor with a thundering shake. Clayface flopped into an arched position on his knees. His shoulders heaved, his heavy breaths audible.

Killua stared down at the monster with cool indifference. He had a feeling the monster's fuel was already starting to dissipate. It seemed this battle was already reaching the ending stage. How fun.

It was time to end this fight; it satisfied his curiosity.

His hand tensed with throbbing veins and nails sharpening into refined claws. Killua sighed, preparing himself for the end of the battle. He closed his eyes, channeling every principle of Nen into the sharp ends of nails:

Ten, Zetsu, Ren, Hatsu, and Gyo.

"Ko," Killua uttered quietly.

He wasn't quite as efficient with this principle as Gon had been, but the technique wasn't foreign to him. Whether this could kill the clay monster or paralyze him from the shocks, Killua didn't know. He internally questioned if it was even possible to kill him.

A crackling, light blue hue enveloped his hand. He had to be careful here. While this condensed aura should amplify the potency of his aura into one single attack, he's leaving the rest of his body vulnerable. He should still expect the worst from this; the rest of his body barred from Nen reminded Killua of the enormous gap in raw strength the clay monster held over him.

Killua bounded forward, arm pulled back, rapidly closing in with his speed in seconds, and he then thrust it ahead. Clayface stood stiff like a statue, his monstrous face wide with terror. The sharp tips of Killua's nails connected, and Clayface's entire form exploded instantly. Killua blinked as the shattered particles scattered around him in midair. His eyes scanned the tiny fragments.

Something wasn't right. These pieces were solid rather than the gush matter that made up the monster. Did the clay monster solidify himself to heighten his defenses against the attack? If that had been true, then it failed.

Killua gasped before his eyes snapped to his left to see the clay monster kneeling at the opposite side of the room. Clayface sported a manic smirk as his arm stretched in a puddle on the floor like he was reaching for something underneath.

"Gotcha!" he exclaimed.

Killua's eyes widened as a mega fist suddenly sprouted from a puddle underneath him. When did that get there? With his Ko evaporating, Killua quickly covered his body with his protective aura. Too defenseless in the air to avoid it, the massive punch collided with his body in a bang, forcing a choking splutter to shoot out of Killua's mouth.

Clayface looked on with glee, giving himself a score for finally landing a punch on this kid for the first time. He could just feel that delicious power of that kid channeling through him; it was so rejuvenating. He stretched his arm in its ascent until crushing Killua in a sandwiched position against the ceiling. The deadly impact reverberated throughout the building, and fragments of the ceiling flung into the now-exposed starry sky.

Killua flailed above as he rapidly dropped from the ceiling. When his body was nearing the surface, Killua widened his eyes at a second incoming punch drawing closer, and he blocked it in time with his arm. Killua winced behind the pressure before being launched at hyperspeeds in an instant.

Dozens of dusted machines, catwalks, equipment, and reservoirs were mowed over by Killua's hurling form, leaving a river of destroyed material in the process — total demolition. Killua unceremoniously crashed flat against the metallic wall, chaining a skin-crawling vibration to ring throughout the building.

Killua dropped to his feet as he hunched over. "Okay," Killua muttered, catching his breath. "That hurt quite a bit."

His mind replayed to the point just a few minutes ago. When had the clay monster appeared in one spot to another? And that's when it hit him. He duplicated himself. He found the opportunity to do it after I cut him in half. What I had been fighting was nothing more than a husk. He knew he had no hope of matching me in speed, so he might've pretended to be defenseless. All in hopes of letting my guard down and waiting for the right moment to strike. I won't let that happen again.

Killua gritted his teeth when he studied his palms. "But why do I feel weaker?"

He looked up to see Clayface trudging to him from the tail end of the destruction. Killua glared at his monstrous foe before charging at him, and he was above the clay monster in a split second before he let fly a blinding kick. Clayface's teeth clashed against each other upon impact. Killua's eyes shifted sideways, and he couldn't hold back a gasp at an incoming mace.

He can see me now! How!? Killua frantically thought.

His arm flew upward and blocked it before it connected, but it didn't prevent him from being sailed to the floor. Killua's back bounced against the tiles before he flipped back to his feet. He straightened his stance with a surprised glare.

His attacks are gradually becoming more potent. Killua observed keenly.

His face drooped at a fast-approaching punch, and he weaved it; it resulted in an ample wave of dust and debris off the floor behind him after the bang. Killua grunted from exertion when he watched the retracting limb as it passed by.

And they're faster, too! What the hell did he do!? Killua's mind raced for possible answers.

"Heh-heh-heh-ha-ha-ha!" Clayface cackled. "Encore! Encore!"

Clayface's trunk-like arms raised above him, and numerous limbs emerged from his back. Each hand balled into a fist before they made a beeline toward Killua. Killua ducked as a punch grazed his hair, and he phased over repeatedly through the barrage of punches.

Clayface's flurry of punches shook the chamber, and bits of rubble flew out of the canopy of fists. Clayface spared no breathing room as he aimlessly bombarded the punches, doing everything he could to suffocate and trap his younger enemy.

His appendages exploded into a mist, and Killua stood in the center. His eyes were tensed and darkened, his whip-like arms swirling ahead of him like a storm. Clayface scowled widely, the technique reminding him of the embarrassing night.

After retracting his arms with an audible snap, Killua flared his Ren and cut forward in a blur, darting across all directions in his trek before bulldozing Clayface with an earth-shattering blow. Suddenly, a sprinkling of clay flew over them, and Clayface's one eye opened wide as he felt his face mushed under Killua's elbow. Clayface swiped down a sword, and Killua kicked his feet against Clayface's frame to hurl himself backward, swiftly avoiding the mock blade. Strands of silver-white hair were left fluttering in his place.

Killua's back slid against the tile before kipping up to his feet. Blood rushed through his veins, his heart pounding, and his pupils dilated through the rush of excitement. In no way did Killua expect his time in this world to be filled with such a thrilling experience. It's been so long since he felt this rush of excitement.

A grin crawled up his cheeks. Oh, how glad he was that the clay monster proved him wrong and even surprised him!

Yes, he could feel the burning hatred for him that oozed from the monster's bloodlust. Killua, though, found himself thankful that this monster condensed his hatred into the power that he was facing.

Killua was honored to have the clay monster as a strong opponent.

Killua disappeared in a blink, and a hellish punch pierced the larger foe's abdomen, earning a wide-open mouth from said foe. Clayface's hand shook before balling a fist and throwing it. Killua caught the hook midair with an open palm, the floor fracturing from the gravity. Killua elevated to Clayface's height and rocketed a well-placed uppercut.

Clayface pushed through and flew a punch of his own. Killua's eyes narrowed before he brought his opposite fist forward and crashed against Clayface's. The intensity of the collision sent an eruption of dust blowing around the brawl.

Robin witnessed the ongoing back and forth with astonishment from the catwalk above. He couldn't help but grit his teeth at the playout. It was inevitable that Clayface's Corrosive Touch had started to kick in, but to see it have the odds to take a sharp turn on such short notice was concerning.

Based on the profile I read, Corrosive Touch is one reason why getting in a fistfight against Clayface is a treacherous battle. With a single touch, not only can Clayface process the DNA of his victims, but he can also take that DNA and copy one's abilities. Robin thought as his nerves tingled his goosebumps. Not only that, his touch will eat away at flesh, and if this keeps up, Clayface will continue to consume Killua's energy, and Killua will eventually run out of strength to fight.

Robin watched the ongoing struggle with a wince, feeling the vibrations from each blow. "I have to do something to help, just this once." He checked his supply of freeze grenades and explosive batarangs in his utility belt. He feared this factory could collapse at any moment.

While a single freeze grenade won't entirely affect Clayface in his current form, a single patch of ice can temporarily incapacitate the clay substance, disarming Clayface from throwing a constant barrage. Although the explosives would be nothing more than a bee sting to Clayface, they could still melt the clay.

Robin turned to Annie, who remained in her curled-up position. "Annie, you should try to escape. Okay?" He told her. A loud crash rang from below.

Annie peered one eye out her knees before raising her head to look at him worriedly. "And what are you going to do?"

Robin glanced at the battle below, "I'm going to help take down Clayface," he replied determinedly.

Annie looked to her knees. "Oh," She said disheartedly. "Just try not to…" She trailed off, not having the courage to finish.

Robin smiled assuredly, "I know."

Killua crashed hard with an explosive boom after being struck by a spiked club from Clayface, enough to create an indent on the floor, which had given way from floor tiles and the concrete underneath.

From the cloud of dust came Killua bursting through with a hardened look, his fist raised. Clayface didn't have time to react as usual, and Killua harshly smashed his fist against the clay monster's jaw, and a shockwave burst around the area. Clayface rolled midair like a fan, breaking through working equipment, not stopping his trajectory until he slammed against the far wall like an earthquake.

Clayface slipped down before touching his knees on the surface. He huffed as he faced the square tiles, his bulky arms supporting him from being prone face-first.

Clayface had already taken more blows from the kid than he could count and felt ready to collapse. The kid should've already been drained dry. Clayface looked up to see Killua across him, covered in scrapes, bruises, and a trail of blood leaking from the corner of his lips if one could squint.

Preparing his trump card, Clayface steeled his arms and channeled all his clay to burst out of his palms. Even if the kid was fast, there was no way he could escape the wide range this attack covered. A devious thought came to mind. No, this attack will devour every inch of this building!

"DIE!"

Clayface roared as he bathed in his bloodlust. A widespread surge of mud gushed out from under his hands. Clayface strained his palms, and the surges immediately spouted above the room, close to the ceiling.

Killua froze as the gigantic shadow blanketed the room, his eyes fixated on the wave. He then hung his head, his spikey silver hair enveloped his eyes. His head snapped up with cold eyes, and the air dropped.

The mudslide ceased its surge, nothing more than a mudfall. Clayface's murderous rage had vanished, replacing it with an intense, unquenchable fear.

He tensed his jaw under the piercing air, almost remembering the feel of needles. He attempted to urge his will to fight against this dark, lightless exposure. But he couldn't move! What the hell was he dealing with?

Lost in his terror, Clayface didn't notice the batarangs hit his back, and a gratifying explosion blew up parts of his back. A thunderous groan omitted from the giant before the mudfall collapsed in a massive splash.

Killua's eyes blinked away the darkness. Curious, Killua gazed up to see Robin standing on the catwalk above with a device in his hand. As Robin glared at Clayface, he chucked a couple of grenades at the massive splatter. White zones glazed over the huddle, immobilizing the slide.

Robin frantically snapped his gaze toward Killua, "FINISH IT NOW!"

Killua stared dumbfoundedly at the boy in red. Had he understood what he said? He was urging him, was he? Killua faced the clay monster with a glare. "Right. It's time to end this." Killua muttered before eyes tensed.

"Ko!"

A sizzling, light blue aura coated his leg. And Killua was utterly astonished that his bare body was on the verge of collapse itself. Rarely did Killua suffer from exhaustion out of a fight. Not since his bloody battle against the Ortho siblings.

With a loud cry from exertion, Killua inserted every ounce of effort behind his leg with the crackling hue before catapulting, and a bluster of rubble flew out in an upsurge from his wake. Killua was upon the confused Clayface in the blink of an eye as he spun midair. Clayface had no idea what was coming.

An air-rippling kick struck his midsection point blank. Clayface released a roar of agony as he coughed out a splutter of mud. Upon impact, Clayface was hurled to the wall, busting through the confines of the chamber, and even then, the momentum wasn't over. Due to the force behind Killua's attack, Clayface ended up bouncing against the floor with his back and began to flip in his trajectory through the wall on the opposite side of the next room, shattering wall after wall after wall with his hulking body until finally crashing through the exterior wall of the factory.

Clayface fell into the dark pit outside the factory, crashing into the ground with a loud boom far below.

A rumbling sound accompanied the debris fanning out at the factory, revealing the toll it suffered from the battle. Robin looked in disbelief around the factory, knowing it was time to escape before its inevitable collapse.

Robin turned in the direction where he presumed Killua was present. "Hey, we-" he paused, unable to detect a trace of him.

He looked around for a bit, not spotting a flash of white. "He's gone," Robin muttered. He shook his head and looked up to where he last left Annie. It was time to get her and get out of this hell hole.

So, Time passed since Robin and Annie got out of the factory before it crumbled into a mass pile of heavy debris and metal. Firemen, officers, and paramedics crowded the yard amidst the rubble.

Afar, Robin observed the professionals' actions during the segment. His tired eyes caught a glimpse of an unconscious Clayface - encased in a liquid tank - being hauled into a SWAT truck before the officers shut it. Commission Gordon was spotted discussing with an officer near the armored vehicle.

"Good riddance, Karlo." Robin said to nobody. "Hope you get comfy at Arkham."

His gaze softened as his eyes landed on Annie conversing with a paramedic as she sat at the edge of an ambulance's haul. He had told her to do anything she could to hide her rather peculiar nature. He couldn't trust the public if word got out about her relations with Clayface; it would only bring more stress into Annie's short life.

"I see you've done work without me." The grave voice from behind almost made Robin jump. Robin turned around to see Batman watching the scene behind him.

He sighed tiredly. "Look, I'm sorry I-"

"It's all right, Robin." Batman cut him off. "You've done the right thing. That's all there is to it."

Robin couldn't believe his ears. Batman admitting that he had made the right choice by disobeying him? What world did he live in? Still, though, it was understandable since it involved saving a life. If he had gone to the manor with Bruce during the day, what were the chances of his encounter with Annie? He shook his head with no desire to dwell on the what-ifs.

Robin gazed forward and was relieved to see Annie sitting silently alone in the haul of the ambulance. He turned to Batman. "Before we go home, can I see Annie for a minute? I just need to talk to her."

Batman closed his eyes as he sighed through his nose. "Go."

Batman didn't know what to think at seeing Robin's face brighten as he rushed ahead. Batman watched as he chatted with her, his smitten feelings for the girl betraying him, and she happily reciprocated his smile.

He looked away to catch Gordon and all the officers taking their leave, with the SWAT truck containing Clayface on the front line of the passage. He squinted his eyes in the distance. His cowl lenses locked with sharp blue ones of a figure standing on a lone hill.

Killua motionlessly met the Dark Knight's gaze. He still had no idea what to think of helping Robin out of the blue, but the next time they met, Killua fully intended to resume his war against Batman. And nothing that happened tonight changed that.

And with that, Killua turned away and walked with heavy steps into the dead of night to Gotham.

Well, that's the end of this short arc. This arc was inspired by the episode from The New Batman Adventures titled, "Growing Pains". A favorite episode of mine from the show, which is one of the most depressing episodes in that entire series.

Now, I had a lot of fun writing this fight. It's probably my favorite part to write in the entire story so far. And yes, I'm a huge fan of endgame fights for arcs.

The next arc should cover Killua's clash against Deadshot, Wonder Woman, and his ongoing feud with Black Mask. Stay tuned.

By the way, let me know of any mistakes I made and I'll fix it.