MHA: Cruel Transmigrator

Itsuki toyed with some water he'd lifted from his glass, making it dance in the air however he wished. He expected controlling liquids to be much harder, but to his surprise, it wasn't much harder than controlling the stack of papers. 

Controlling the intangible force of his quirk was almost second nature to him. He split the water into smaller parts, creating multiple swirls of water traveling in the air like snakes.

Itsuki soon decided to try something else. He returned most of the water to the glass and guided a single swirl to his hospital bed mattress. He wanted to see if he could pull the water out after it had been absorbed into the fabric.

This proved to be much harder, he found it difficult to pull the water out because he didn't know where it was. Controlling something with his eye closed was effortless, like moving a pen from one hand to another, but only if it was already in his control. Like moving a pen from hand to hand would be if the pen wasn't in his hand.

Even though Itsuki couldn't remove all of the water, he felt elated. His quirk had a lot of room for growth, in the future, he might be able to use it as a sixth sense of sorts to see what was happening around him.

'I wonder if I could stop someone's heart from beating or make their brain explode ' Itsuki thought looking at his mother, who was nervously fiddling her finger in her lap.

Inko anxiously tapped her foot against the floor waiting for the doctor to arrive. She was acting restless, lost in her thoughts, and not paying any attention to what her son was doing. 

The doctor soon arrived and began to explain a bunch of boring medical details and some less boring details. Apparently, Itsuki had gotten injured while training on a nearby beach filled with trash, presumably due to overusing his quirk.

The doctor explained that damage to his brain was so severe the surgeons thought he would certainly die. But he managed to survive due to his quirk being a mutated one. His brain turned out to be exceedingly durable compared to a regular one and even had regenerative properties.

'That explains why I have such a high degree of control over my quirk. If I remember correctly, people with mutant quirks have greater control over their abilities without training.'

His quirk seemed to function more like an emitter type quirk rather than a mutant one. Mutant quirks often result in visible changes to the body like extra arms or pink skin and in some unfortunate cases, you get a spray bottle for a head.

Itsuki's recovery was swift and by the next mourning, he was already discharged and allowed to return home. On the ride home Inko kept telling stories of his childhood, trying to rekindle some memories in him.

"I remember when you used to play heroes and villains with your sister when you were kids." 

'Sister?' 

Itsuki turned to look at his mother with a surprised expression. Inko didn't notice this as she kept her gaze on the road and just continued her story.

"Izumi always wanted to be a hero and you just accepted your faith always reluctantly playing the villain. Such a shame she doesn't have a quirk..." Inko ended with a somber remark.

'I guess the protagonist getting gender bent shouldn't be too unexpected. Inko has a whole other kid after all, one with a powerful quirk, who was never mentioned in the series at all, or at least in the parts I watched.'

Itsuki took a deep breath and looked straight ahead at the busy streets of Tokyo. It took a weirdly long time for her mother to mention that he had a sister in the first place. Inko must have just assumed he remembered Izumi, it was safe to assume that because he'd pretended to remember her too.

'I wonder what else has changed. If Izumi has had a brother with a quirk her whole life she'll likely be a lot different than the protagonist in the anime.' Itsuki thought as he stared at the road.

He tried to think of the possible ways his presence could have affected her growth as a person but quickly gave up. There were just too many variables he had to consider. Trying to predict something like that was pointless, so he just had to wait and see.

'I just need to hope that butterfly effect doesn't completely derail the story's canon.' 

The rest of the car ride was spent in somber silence until they arrived at the apartments. Even from the outside Itsuki could tell that the apartment was small, the building was thin and the space between the balconies was miniscule.

"Izumi we are home!" Inko yelled as we entered the small apartment, a pair of rapid footsteps could be heard and soon a petite green haired girl ran into the narrow hallway.

"Big Brother! You're back!" Izumi cried out, her innocent angelic face lighting up with excitement as she saw her brother, rushing forward to embrace him into a tight hug. Izumi had a petite yet curvy figure. Her loose t-shirt hugged her full chest and her tight jeans traced along her shapely legs and round hips. She had inherited her mother's curves for sure.

Despite this her overall appearance was still cute, mainly due to her innocent face and short height, half a head shorter than her already short mother, her short and messy green haired head barely reaching Itsuki's chest.

"I am glad to see you too Izumi." Itsuki said with a smile, gently responding to the affectionate embrace by ruffling his sister's messy green hair, which caused her to giggle adorably.

'I think I'll find myself enjoying this new family a lot.' he chuckled to himself.