It was the year 100 AG, not that the spirits cared, when Vaatu sensed the greatest potential for chaos.

The scales of the world's balance had been tipping in his favor as of late so it was really no surprise. The hold on his prison had been weakening since Avatar Roku's time, allowing him to influence lesser spirits into stirring up trouble in the human world. He still couldn't leave, not physically at least, but when Vaatu sensed Raava's weakness, he knew it was time.

There wasn't much he could do with the Avatar on a boat but he was heading toward the Fire Nation capital so Vaatu supposed he could wait. The dragon and snake caught his interest though. He could feel the Blue Spirit glaring from within the boy when he lingered a bit too long but Vaatu didn't let that deter him. He wasn't doing anything, not yet, and when he did, it wasn't like a trapped spirit could do much to stop him. Ironic, coming from Vaatu, but still true.

Maybe a little too much of his influence bled through, judging from how badly the Avatar was panicking. Or maybe this Avatar was one of the weaker willed ones. Either way, the heavy stone of hope settled in Vaatu's belly. Things would go his way. He just had to be careful. Or more accurately, precise.

"Ready your sages," Vaatu whispered heavily into Ozai's ear. The man didn't react, not visibly, but Vaatu knew he'd heard him. People like Ozai had a special connection to dark spirits like himself. Ozai may not know it but he was sure in everything he did and he wouldn't ignore any inkling telling him how to win. Neither had the Fire Lords behind him. A very good trait for a leader to have, or at least it was good for Vaatu. During times like these where the figurative chains of his prison were weakened, it was an easy way into the human realm.

It was entertaining, in a way, to watch both Zuko and his family prepare for the upcoming battle. Normally, Vaatu didn't take much interest in the lighter spirits but most of the Fire Lord's preparations were just barking orders right now. The Avatar and his companions were far more interesting.

What happens to children when they're forced to grow up too fast? Vaatu wasn't terribly familiar with human growth and that made it all the more entertaining. The Avatar's companions had gotten him to calm down but they were still going to battle and the nervous energy was buzzing through all of them, even Oma and Shu's girl. She always tried to look so strong. Didn't she see she was as puny as the rest of the humans? Well, maybe not the rest of the humans. That serpent spirit inside her was really something. Maybe Vaatu could use that later.

The others tried to hide it too. The Avatar was a symbol and he knew his allies needed their pillar to be strong. The Water Tribe boy was a leader. He needed to set an example. The Waterbender was holding her head up high because that was all she knew how to do. Only Agni's boy let some of that fear show. Some of that delicious, delicious fear. It'd been a long time since he'd been a prince, just as long since he'd gone home. He had a weakness Vaatu loved to see.

Azula was the total opposite. She too had been forced to grow up but, as opposed to Zuko and his companions, she thrived, at least as far as Vaatu could tell. Again, he didn't know much about the ways of humans. She looked pristine though, not a hair out of place. She looked far more ready than the Avatar's ragtag crew with their wood and bone weapons and stolen ships. Azula even had armor. Such a small thing and it made all the difference. The Avatar truly wasn't ready for what was about to come.

Vaatu would make his defeat all the more crushing.

Granted, Zuko and Toph put a pretty big dent in the Fire Nation's plans. They were expecting an attack from the sea. There was no way for them to prepare for simultaneous attacks from above and below. Both Zuko and Toph transformed the moment they hit the ground. Zuko stretched into his more serpentine form, mirroring Ran and Shaw's glory, and launched himself into the sky while Toph sank into the ground below. They wrecked havoc unlike any the Fire Nation had ever seen.

Few living warriors had seen dragons before. Zuko wasn't as big or fearsome as his predecessors but he was still plenty strong. He spat fireballs down on the city, forcing firebenders to bend the fire away from them instead of focusing on the Water Tribe warriors advancing on them. Toph shook the earth below their feet, keeping them wary of when she'd pop up and swallow one of them. For more than a few moments, it looked like the Avatar and his companions would be victorious. Vaatu knew better.

"Who are you?" Yue asked, staring at Vaatu with wide, human eyes. He tried not to look surprised. He wasn't expecting to have enough strength to be visible. Azula must have shaken up the Avatar pretty badly for the forces of balance to tip this much in his favor.

"Just an observer," Vaatu said passively. He glanced back at the battle below. The sages were nearing the battlefield, a few dozen armed nonbenders in tow. It was almost time. "Are you going to cover the sun anytime soon?"

Yue scowled. "I'm not doing that."

"It's the path you're on."

"I'm more than just the moon. I have some control of what the moon does," Yue told him, glaring. "I'm not cutting Zuko off from Agni in the middle of a battle."

"The Water Tribe boy's strategy relies on it," Vaatu pointed out. He tried to sound… What was the word? Interested? Empathetic? He'd much rather do this his own way but even if he had enough strength to be visible to the other spirits, he didn't want to push it.

"Sokka will just have to deal. They're doing pretty well without my help."

Vaatu hummed. "We'll see."

He didn't strike then. It would be a cinematic moment but Yue would see it coming. He waited a bit longer, watching the Avatar struggle to find Ozai and the rest of the battle rage outside. War was entertaining but he had to keep an eye on the sages. They were key to this. When they were finally in position, Vaatu struck.

Vaatu reared up to his full height, spreading all his appendages and letting his tentacles thrash wildly. Yue caught it in the corner of her eye and turned but she was too slow. It was rather easy, actually, with her human shape and all. Wrapping all his tendrils around her, Vaatu ensnared Yue and began dragging the moon before the sun. "Don't struggle. Eclipses don't last long. It just needs to last long enough for the Fire Nation to capture your beloved Zuko."

"Wha-? They're going to-" Yue cut herself off and began trying to wrestle her way out of Vaatu's bindings. "Agni! Agni, help!"

Oh right. Agni. The moon went in front of the sun. Maybe he should have thought about that before grabbing the moon spirit. Vaatu felt a roaring heat appear behind him and lashed out with his tail, not quite hitting the great spirit but keeping him back enough that Vaatu didn't have to worry quite yet. "Keep back or she gets it."

Agni's expression soured. "You dare threaten the moon spirit, Vaatu?"

"I dared threaten the light spirit," Vaau responded, tone mocking. "The moon spirit doesn't compare to that."

"She is more powerful than you think, Vaatu."

Vaatu scoffed. "She still clings to her moral form. She is far from powerful."

"Thanks for the idea," Yue responded and suddenly there was a sharp pain in one of his tendrils. Vaatu tried to pull it back but something caught him. There were teeth digging into him, and not those flat things humans had. These were fangs.

Scales spread across Yue's human body before Vaatu could even blink and soon her human shape was being replaced with something much more serpentine, and something much, much bigger. All the indents that made it so easy to hold onto her human form disappeared, Vaatu's grip slipping, and Yue soon became too large to hold onto. The sea serpent roared and snapped her tail, throwing Vaatu off her and allowing her to stretch out to show off her new form in all its beauty.

"Angi was right," Yue said but her lips didn't move, not like before. Spirits didn't need to speak the way humans did. It seemed Yue was finally getting the idea in her head. "I'm more powerful than you think."

"Perhaps," Vaatu admitted, "but no matter. I've already done everything I set out to do."

Alarmed, Yue looked down at the mortals below. Zuko had dropped out of his dragon form into something halfway between the quadrupedal dragon and his human body. Nonbenders surrounded him tugging on thick chains to try to constrain his wings. Toph was nearby, similarly struggling to maintain her spirit-gifted transformation. Vaatu hadn't expected that, nor had he noticed when it happened. Toph didn't have a connection to Agni. Maybe grabbing Yue had severed the connection in some way? She was still closer to full transformation than Zuko. Then again, she only had one other form, no intermediate stage. Vaatu didn't ponder it. They were in the Fire Nation's clutches, just as Vaatu had hoped.

"Who are you?" Yue asked again, voice little more than a whisper.

Vaatu glanced back at her, feeling his presence grow even stronger as the Avatar was forced to admit defeat and flee. "I'm Vaatu, the spirit of darkness and chaos, and I suspect you'll be seeing a lot more of me."

Truthbetold, Vaatu expected to be sent back to the prison where his body awaited after the battle. He wasn't though. Darkness had won the battle and Vaatu gained a sliver of power because of it. With the Avatar still alive, Raava still held the favor of the scales but the day of Harmonic Convergence was nearing. It was still too far off for Vaatu to truly get his tentacles into this mess but it was enough that this war may feed him enough strength to fight as Raava's equal the day of their battle came.

There wasn't much to meddle with at the moment though. That was okay. Just watching made Vaatu feel that much stronger. Vaatu had no sympathy for Agni's posse. He was no light spirit but he took sides so his family and allies did too. It gave Raava the edge she needed to win a couple of their fights and Vaatu held a grudge. Oh, how he wished Toph had a real spirit in her. He'd love to watch two spirits suffer but watching the Blue Spirit writhe was more than enough.

"See, Father?" Azula stood in an underground room that Vaatu could only assume was a prison cell. Zuko and Toph were before her, skin still dotted with scales but nearly entirely human, bound by Dai Li agents and metal bindings. Vaatu could sense Toph working her bending into them but used his presence to smack her hand before she could make much progress. Metalbending would be an interesting change to the world, one Vaatu would love to see, but not quite yet. He couldn't have her escape before the Dai Li worked their magic. "I told you Zuko was still alive."

"I shouldn't have doubted you, Daughter," Ozai replied, eyes never leaving Zuko. Zuko ducked his head, trying not to look at his father, but Ozai strode forward and grabbed Zuko by the face, forcing him to meet his gaze. No one in the room missed the way Zuko flinched at the contact. "Now, where have you been all this time, my son?"

"He's no son of yours," Toph snarled. Azula shot an ember in her direction, saving Vaatu from having to waste any energy hitting her himself.

Ozai ignored the girls, remaining focused on Zuko. He shook his hand, jostling Zuko's jaw. "Well?"

"I- I was in the Northern Water Tribe," Zuko choked out, eyes wide as Ozai stared into them. "I met the Avatar when Zhao killed the moon spirit."

"I don't care about that," Ozai snapped. His fingers began to heat up, not enough to burn but enough to make Zuko stiffened. "How did you contact the spirits?"

"What?" Zuko looked genuinely confused and that made him slip up. Ozai shifted his grip, forcing Zuko's head up. "I don't know what you mean, Father!"

"You transformed into a dragon," Ozai clarified, sounding annoyed that he even had to say it. "How? Why would the spirits choose someone like you?"

"Mom… Mom never told you?"

"She told me many things. She told me she wished you were the son of another. That you were more like that treacherous dog than me," Ozai said, expression unwavering as shock spread across Zuko's face. Vaatu chuckled. He may not understand human families but he loved their drama. "She told me she didn't want to train your firebending, even though that was the only reason she was chosen to be your mother. She also told me she killed my father on your behalf."

Zuko blinked, unsure how to answer. Then, he abruptly remembered who exactly was holding whose face and the words came tumbling out. "I- um, I guess she didn't tell you about me. I've always been able to transform. I, uh, I found out my spirit was weak at birth because the Avatar was gone and the cycle got confused so another spirit filled in."

Ozai's hand dropped.

Azula snorted. "You really expect us to believe you were meant to be the Avatar if that little bald kid died?"

"Not just him," Toph jumped in. "Me and the new moon spirit too. We're just lucky like that."

Vaatu saw something spread across Azula's face, something he didn't understand. Zuko's next words cleared it up. "Azula was born lucky, I was lucky to be born. That doesn't sound quite right anymore, does it?"

By now, Azula was seething, Vaatu could tell, but she didn't dare let up her perfect presentation in front of her father. Ozai no longer had eyes for her though. Zuko was the sole object of his focus. "Interesting. Two potential Avatars will supplement the Fire Nation's forces quite well."

Toph laughed loudly and obnoxiously. "You really think we'd fight for you? Keep dreaming!"

"I didn't say you had a choice." Ozai turned to Azula. "I trust your Dai Li agents can handle this?"

Azula nodded, folding her hands behind her back. "They can. You will have two brainwashed monsters at your feet by sunhigh tomorrow."

"Actually-" one of the Dai Li agents started but silenced himself at a glare from Azula. "Yes. That is right, Your Majesty. We'll wipe out any free will left in them for your service by noon tomorrow."

Toph chose this moment to bend the metal cuffs keeping her hands together. Impressive but Vaatu didn't want to watch another fight right now. He wanted to see whatever this brainwashing process was as soon as possible so he slapped her wrists again, forcing Toph's will over the metal to die before she could rip a hole big enough to get her hand through. She was a feisty one. Vaatu would miss that about her.

Ozai didn't say anything, merely nodding in acknowledgement and turning to leave. Azula followed behind, not a step out of place but Vaatu could tell Toph and Zuko's words had gotten under her skin. He'd follow up on that later. For now, Toph, Zuko, and the Blue Spirit's screams were plenty to keep Vaatu occupied.