"What exactly are you doing again, Donnie?" Izuku stared at her friend standing next to a sleeping April whilst Donnie was working on some form of mutagen. It had been a few days since the incident with Izuku losing control of herself. After that she's taken some meditative lessons with Splinter in order to keep her rage in check. It's done its part to help her keep her rage under control.

For the most part.

"This is supposed to be a batch of retro mutagen, which we will use to mutate April's dad, you and master splinter back into humans. Assuming it works that is. " Izuku had been given the shortened version of who April's father was and what had happened to him. Needless to say she feels bad and intends to help return him to normal. Donnie had been working for the last few days in order to try and create a reverse mutagen or, as Donnie calls it, Retro-Mutagen. With it Donnie would be able to turn April's father back into a human.

And, maybe just maybe, have enough to turn her back into a human as well. However this was what led to Izuku's current predicament. Does she even want to return to normal? As much as she misses her old body, she has gotten used to her new one for the time she has had it. Are there issues? Yeah but then again no one's perfect. Not to mention all the added pros more than outway the cons.

Donnie used a strand of April's DNA and began to mix it with the mutagen and some of his own chemicals. Donnie placed the sample under the microscope as looked to see if it had done anything. Izuku stood patiently, praying with Donnie for it to work and for them to be able to help April's father. It seemed to have turned out well as Donnie was quickly celebrating. Soon the other turtles and Splinter walked into the lab having heard Donnie celebrating his success.

"What's all the commotion about?" Leo asked with Mikey, Ralph and Splinter walking in behind him.

"I was able to finish the batch of retro mutagen" Donnie spoke, holding up the vial of his latest breakthrough. "With it we can turn April's dad human again" Donnie held one of the beakers in front of master Splinter "and you too sensei."

"Human once more" Splinter looked at the beaker, before gently pushing it back to Donnie. "Save April's father, and then I will… Consider it" and with that Splinter walked off, more than likely to contemplate the same question she is. Mikey snatched the vial before asking what he looked like prior to mutating, completely forgetting he was just a normal turtle beforehand. Donnie quickly snatched it back, the turtle mentioning that he only has two doses and currently can't make more.

"Izuku, I want you in on this" Leo spoke to her, getting the others' attention. Before she could respond, Leo raised a hand to stop her "what happened last time was an accident and, now that we know what not to say we can keep it in check." Izuku looked at the others, all of them expecting what she would say.

"Alright guys, let's go bat hunting," Izuku said, the crew smiled at Izuku's resolve.

'Ninth' a male voice whispered to her. Izuku looked around the lab to see if she could find the source but had no such luck. She simply shrugged it off before going to join the others, unaware of her eyes briefly glowing a bright green.

LATER

The turtles, April and Izuku (now in her costume) all stood on top of a building, looking at a bat mutant barging its fangs into the neck of a billboard with a massive woman on it.

"April, stay back, we don't want to rile up your dad like last time. Izuku, if he makes a break for it, use your quirk to pin him down whilst Donnie administers the antidote. But please-" Leo was interrupted by Izuku.

"Be gentle, don't worry I can handle it. If it makes you feel any better I have some ideas brewing on how to hold him." Izuku spoke back to Leo as he motioned for the group to advance. The turtles were just about to administer the antidote when something flew by, spooking Donnie and making him drop the retro mutagen. April's dad quickly flies away, the mutant avoiding one of Izuku's arms (much to her shock) and the reptilian girl lands behind her comrades. The group turns to find a man with the head and wings of a fly, his right arm a giant claw.

"Turtles. G-g-give me the retro mutagen" the fly man spoke, the mutant now standing atop the billboard that April's father was on.

"Yikes that is one UGLY muta- wait a sec" Izuku knew the mutants voice and immediately put two and two together. "You're that nerd looking guy who works with Shredder, Stickman was it?"

"IT'S BAXTERS S-S-STOCKMAN. And I will be taking that retro mutagen" Stockman charged at the vial, but was unable to get to it before Izuku dropped and kicked him through the billboard. Izuku used her tail and grabbed a hold of the retro mutagen as Stockman took to the skies.

"You want this?" Izuku waved the vial in front of her "Then come and get it Stickman."

"ITS S-S-STOCKMAN" Stockman quickly lunged at Izuku. However due to Stockman not being a fighter she easily dodged his pitiful attack by moving to the mutant rights and hit him in the face with a left hook. Stockman crashed into the nearby building before charging back at Izuku who lunged right for the bug scientist. Izuku tossed the mutagen high into the air, gaining Stockman's attention. Izuku then wrapped her tail around Stockmans neck before spinning around and sending him crashing into a nearby car.

Izuku gripped onto the fire escape ladder and hung off it like she was spiderman. "Is that all you got or are you thirsty for more? "Izuku asked as she caught the vial of retro mutagen in her hand.

Stockman, quickly realizing he wasn't getting anywhere, immediately went to plan B and flew not for Izuku but for April. The bug grabbed the girl and flew out of range for Izuku to hit him. "Bring the retro m-mutagen to my lab or else the girl m-m-mutates with me" and with that, Stockman flew off with April attempting to kick the bug man in order to let her go.

"Well shit" Ralph said, something Izuku agreed with. This plan would have gone well but of COURSE the universe decided to screw them over.

'You're a failure, as per usual' her male voice spoke in her head, something Izuku simply waved off.

LATER - TURTLE LAIR

Izuku and the turtles quickly got into the sewers to regroup and replan. Leo also saw to getting Casey involved as well, as it would help to lighten the load. "Alright, the plan is simple. Whilst me, Ralph and Mikey handle wrangling April's dad, Izuku Donnie and Casey will act as the rescue team."

"It's time for -" Mikey used a smoke bomb only to come out in some sort of bug/moth costume "the return of TURFLIGHTLE DAWG. BUZZ BUZZ" Izuku had to fight to hold in a giggle.

"Are you sure we should use both vials? If we lose them both we won't be able to save Izuku or Master Splinter." Donnie pointed out something Leo was having a tough time dealing with. Even if this mission went off without a hitch, they're still gonna have to choose between Izuku or Master Splinter.

"I believe Izuku should take the retro mutagen" Splinter's voice cut through the tension like a knife. "However I believe she and I both agree to keep BOTH on hand in case we need it for Kirby. Whilst we may not be human, we were both able to keep our humanity, something I cannot say for Mr. O'Neil." Izuku nodded, agreeing with her sensei. As of right now, the main objective was to save April's father. Once he returned to normal, then they could focus on reversing her and Splinter's mutation. With the plan in motion the team splits up with Leo, Ralph and Mikey going for Mr. O'Niel whilst her group went to find April.

After making it into Stockmans lab, the three teens stealthily infiltrated the building. When they entered they found April dangling from the ceiling by a rope right above a massive vat of mutagen. When the three teens land on the ground, Casey ends up getting bugged out by a fly. When he kills it, the clap echoes throughout the warehouse.

Stockman turns over to them "where is my m-m-mutagen."

"We'd rather give you a knuckle sandwich before giving it to you" Cassie spoke as he equipped one of his hockey sticks, Izuku charged up OFA and Donnie brought out his techno staff.

"No mutagen, no trade" Stockman spit some acid on the rope holding April up as it began to disintegrate. Izuku quickly charged up OFA as she began running towards April.

"Donnie, you and Cassie hold off Stockman, I'll get April." The two boys nodded and charged right at the fly whilst Izuku climbed up the wall before she jumped to the ceiling. She jumped from I-beam to I-beam as she inched closer and closer to April. Izuku was just inches away when the rope snapped. Without thinking, Izuku leapt down and reached out her hand.

'CATCH HER IZUKU' all of a sudden Izuku felt a twinge of pain in her right arm before her glove was torn to shreds as a series of black and green tendrils sprung out from them and wrapped around April. Izuku quickly grabbed the part of the rope still attached to the ceiling as April hung just above the vat of mutagen.

To say April was surprised was an understatement, not only was this definitely NOT a part of her mutation but it also definitely wasn't her quirk. She didn't get to process long before Stockman spat his corrosive acid onto the tendrils, causing Izuku to yelp in pain as well as them snapping and realing April into the mutagen.

"APRIL" Izuku yelled as Stockman dove for the mutagen. Izuku's eyes turned red as she kicked off the ceiling and launched herself at Stockman, the tendrils quickly forming a massive fist around her arm as the black and green mass SLAMMED into Stockman and sent him flying into the wall. Izuku landed on the outer rim of the massive vat of mutagen, turning back in hopes of seeing her friend. Izuku saw a few bubbles form on the surface before what she assumed was a mutated April. The mutagen barrier broke, revealing a completely unchanged April O'Neil, shocking Izuku.

"Y'you're okay?" Izuku extended a hand to her friend "I'm so sorry for dropping you."

"It's fine, besides at least I'm no mutated"

Izuku put a hand to her chin "wonder if thats why Donnie was able to make the retro mutagen?" Izuku's musings were cut off when an explosion went off in the lab. Everyone looked to see Rahzar and several foot bots at the door. There was also a man with black hair, blue eyes and burn scars all over his body.

"That guy is new," April pointed to the burned man.

The newcomer stepped forward "damn, you're all ugly." The burned man spoke in perfect Japanese, which took Izuku for a loop given she was so used to people speaking english. The man ignited blue flames before launching the attack at everyone. Donnie, Casey and Stockman all dodged the attack as it collided with the mutagen tank shaking the structure. Izuku picked up April bridle style before jumping off the tanks as it began to topple over. Izuku thrusts her arm forward and the black tendrils reappear before latching onto the ceiling. Izuku uses it to swing to the window and escape the building, Donnie and Cassie aren't far behind.

"I have no idea who that is but I don't like him" Donnie says as they all get into the Shellraiser. The engine starts up as the car drives away, with Stockman and the foot clan not far behind. The fire user drives his own bike, with the front bike having a massive skull as the front bit and it also being ON FIRE.

https/en.m./wiki/File:Ghost_rider_

"I have no idea who that is but I SOOO want that bike" Cassie arms the trash cannon and fires it at Stockman and the biker's. Stockman grabs the trash and begins to eat it, whilst the foot bots begin to lose some of their members. Rahzar sliced up the trash and the fire user burned it to ash.

"That is so NASTY" Izuku comment's as she begins to think about how this guy's power works. His power clearly works like Endeavor's but his power output seems much higher given the blue flames. However his durability seems to be worse if the burn marks are anything to go by. Izuku activates the oil slip which manages to cause the footbots to crash whilst the fire user and Rahzar jump from their bikes and continue their pursuit on foot.

"OVER THERE, LOOK" April pointed at Leo, Ralph and Mikey who were all luring April's father. Izuku knows they can't deal with April's father and Foot Clan so she opts to take care of them.

"You guys get April's father cured, I'll handle the foot" Izuku exits out the roof and leaps off. Izuku kicks Stockman into a wall as she lunges at Rahzar and the flame user. She Broly elbow closelines Rahzar whilst using her tail to smack the flame users bike. The two go tumbling down to the ground whilst Izuku lands on her feet.

"So, who's your friend Bradford? I didn't realize Halloween was in season today" Izuku joked as she lunged for the two villains. The scarred man released a volley of blue flames, forcing Izuku to jump onto a nearby lightpost.

"The name's Dabi, you better remember. It'll be the last name you ever hear" the now named Dabi launched more flames at Izuku who dodged once again. Despite her being a fair distance away, she could still feel the heat of the fire. As Izuku landed she was forced to dodge a strike from Rahzar and kicked the mutated dog in the gut, sending him flying into a car. Izuku dodged a series of flames once again from the fire user.

"Gotta say, wasn't expecting a knockoff of Endeavor to show up today" Izuku noticed the man's smile disappear as he lobbed more flames at her. Seem's the mention of the number two hero of Japan was a sore spot, which is something she could use. Guess it was time to pull out the ultimate Mikey move.

Trash talking

"Ah c'mon Endeavor has better aim than that" The man's neutral face turned into a scowl as he lobbed more flames "C'mon I've seen Endeavors fire power and I've fought his youngest kid before, neither of them had aim so bad it would make a stormtrooper jealous."

"Quite you" Dabi launched more flames at Izuku, his voice seeming angrier than before. Unfortunately all his angry tone did was simply adding more fuel to the metaphorical fire.

"Ah c'mon don't tell me that's all you've got. By the way are you sure you're not related to him cause the blue eyes and fire really aren't helping." That seemed to push him over the edge as Dabi yelled with fury, launching even hotter flames at the mutated girl, forcing her to land on the ground.

"I'M NOTHING LIKE THAT BASTARD" Dabi yelled as he charged in an attempt to close the distance. This was a mistake as Izuku speed blitzed him and sent him flying down the street. Izuku didn't have time to celebrate as Rahzar attacked once again. Izuku used her superior speed to dodge his attacks before using her tail to grab him by the next and slam him into the ground face first. She notices Dabi approaching from the side and tosses the mutated ninja right at the burned man. Izuku turned around just in time to see the turtles fighting with Stockman over the retro mutagen vial.

And said vial falling towards the ground.

Izuku puts OFA into overdrive and charges right forward for the vial. She noticed Stockman going for the vial out of the corner of her eye. She releases the black tendrils and has them go after/stall Stockman. Stockman didn't have any time to react before Izuku's claw's wrapped around the vial as the girl tossed it right at April and Casey, who was now riding on the back of Kirby. April caught the vial and stabbed the needle of the vial into Kirby, the retro mutagen beginning to do its thing as Ralph and Mikey catch the trio in a blue tarp as Kirby begins to turn back to normal. The three crash onto the ground as the heroes all land around them, hoping to see Donnie's retro mutagen work. Movement was seen underneath the tarp as Kirby began to move.

"Ugh, what happened?" Kirby asked as his normal, humanoid head appeared out of the tarp.

Everyone gave a sigh of relief as April hugged her father, happy to see him being returned to normal. "It's a long story, dad," April reassured her father.

Leo places a hand on Donnie's shoulder "nice work Donnie."

Donnie thanks his brother for the praise as he pulled out the second retro mutagen vial "Now then let's get home and-"

"LOOK OUT" Ralph tackled his brothers to the ground, causing the retro mutagen vial to go into the air, as blue flames were sent their way. Unfortunately the fire directly impacted the vial, destroying it.

"NO, THE RETRO MUTAGEN" Donnie began to look at the melted vial as there was now nothing left. Izuku growled as she stared at the culprit.

"I am TIRED of this, NOW EVERYONE GETS BURNED" Dabi roared as he began to power up his flames, Rahzar and Stockman right behind him.

"Y-y-you IDIOT, you d-destroyed the r-retro m-mutagen" Stockanm berated his 'teammate' who simply scoffed at the bug man. Leo began to draw his blades, only for Izuku to put her hand in front of him.

"I'll handle this Leo, you get everyone to the shellraiser" Izuku punched her fist into her open palm as she cracked her knuckles. "Alright then, let's finish this" Izuku stepped out into the middle of the street and reeled back her right fist. The black tendrils resurfaced as they began to swirl around Izuku's hand, with those not present when it happened being taken aback by the strange power. Dabi's flames began to heat up to insane levels as he decided to mimic a move Izuku had seen before. From Endeavor

"FLASHFIRE FIRST; JETBURN" Dabi unleashed a blue beam of fire that went straight for Izuku, the reptilian girl remaining in place.

"DRAGON. OF. THE DARKNESS. FLAAAAME" the black tendrils formed the head of a massive dragon as the beast whirled around its creator before beginning to clash with Dabi's attack, the fire user taken aback by the attack. The energy dragon proceeded to devour Dabi's attack, with it catching fire in the process, before crashing into Dabi, Bradford and Stockman. The attack dragged all three villains with it before crashing into a building under construction at the end of the street, the impact and intense heat causing it to collapse.

The attack took everyone, even those who were present for Izuku unlocking this power, off guard. Izuku hadn't even had this power for a full hour and she's already making up attacks with it.

Izuku turns to her friends "let's get out of here before the heroes show up." Leo nodded as they all entered the shell raiser and left the scene, leaving the villains to be arrested. Unfortunately for the heroes, the three bad guys were swallowed up by a purple vortex as they all got in the shellraiser and drove away.

LATER - TURTLE LAIR

The turtle's and co all pulled into the lair, the gang all celebrating their recent victory. "Izuku that was awesome dude, who'd you even do that?" Mikey walked out of the trailer, with the crocodilian girl right behind him.

"I got some weird power up when we went to save April, like some sort of energy manipulation. I just shaped it in the form of a dragon and," Izuku thrusted her fist forward making a fwoosh noise.

"Gotta admit, that was pretty badass" Ralph spoke up. Splinter walked out as soon as he heard them talking.

"I see your mission was a success," Splinter spoke, noticing Kirby (now clothed) standing with them.

"Yeah, though we lost the other goal of retro mutagen. Izuku managed to take down Shredder's goons with her new power," Donnie spoke, gesturing to the turtle. Splinter looked at Izuku as she made the tendrils reappear.

"I must say, this is quite the fortunate turn of events. I am proud of you, all of you. Even if the retro mutagen was lost, so long as Kirby was turned back to normal I call this mission a success."

Leo placed an arm on Izuku's shoulder "nice job Izuku, you managed to take down Stockman as well as help us save April's dad."

"NOW IT'S PIZZA PARTY TIME TIME, WOW" Mikey said going to the phone to order a celebratory pizza.

"I'm gonna take a quick nap, I am tired from using my new power. Wake me when the food comes" Izuku walked down to her room and flopped onto her bed, sleep quickly taking her as she closed her eyes.

IZUKU - MINDSCAPE

Izuku quickly found himself in a black void, currently in his old body. Most of his body was covered with the same black energy that his new tendrils were made up of. He also found himself before right figures, none of which he recognized but had a feeling he knew who they were.

"Ninth," Yoichi Shigaraki, the first user of one for all, spoke up first. "We need to talk"