Jack looked at his sister who was smirking at him. Her yellow, metallic-looking hair and eyes seemed to show her angry and cold nature that she had nowadays, along with the smirk showing her slight disdain for others.

Jack turned his attention to the girls surrounding her.

Most of them looked like delinquents, each of them wearing revealing clothes and having some kind of weird make-up on. Each of the girls was looking at Jack like a thirsty women in the desert, causing bits of disgust to crawl up from deep within Jack.

'I'm your leader's little brother, can't you at least control your lust?'

Jack disregarded the lustful stares at his face and body and looked his sister dead in the eye. "Hey sis, can you lend me some of the girls here? I just unlocked my ESP powers and I want to spar with someone for a bit."

Mikasa squinted her eyes slightly as she looked at Jack's now-blood red eyes. "Why'd you need to fight them? You could spar with me, your dear older sister~" her voice seemed warm but Jack wasn't stupid enough to believe her voice when her eyes looked as cold as ice.

'My dearest sister? If it wasn't for your power...if only...'

Before Jack could answer her, the least delinquent looking one out of his sister's gang spoke up for him. "Mikasa, Jack-chan probably understands that you'd wipe the floor with him so he wants a more suitable opponent~" the girl had dyed blonde hair and olive colored tanned skin but her amethyst purple eyes were what really popped out when Jack looked at her, that and the playful seductiveness floating around in them.

"You're right about that, Aiko-nee." Jack wryly smiled when faced with this woman. She was his sister's childhood friend Aiko Tanaka and while she didn't cast such openly lustful gazes at him like Mikasa's other friends Aiko was obsessed with Jack and wanted to secure him as hers.

Jack didn't necessarily hate Aiko but he didn't appreciate what she did to his sister, such as leading her down the path of starting a gang.

"Hmm, so what do you suggest we do Aiko? Let you go up against him? Ha! Fat chance, you'd eat him alive." Mikasa was aware of her best friends obsession with her brother but she did nothing to stop it, even when she knew it made Jack uncomfortable; she found it amusing.

"Ehhh? Me? Eat up Jack-chan? No chance. Hahahaha!" Aiko started laughing along with the others while also casting flirtatious glances at Jack.

'Why does this always happen...?'

Mikasa seemed to be thinking about who to send to fight her brother and then her eyes landed on a plain looking girl with a black face mask covering her mouth.

"Oi! Akane, go and spar with my brother. Fumiko set up a barrier for then, will you?" Mikasa spoke quite harshly to both the plain girl, Akane, and the girl sitting next to Aiko but they seemed used to it and did what she asked.

Akane walked towards Jack and he backed away a bit to make space. Jack thought that they were lucky they had such a large back garden.

Once there was sufficient space, the barrier girl, Fumiko, set up a square barrier around Akane and Jack with the measurements of around 10 meters in length, 7 meters in width and 4 meters in height.

Jack looked over at Akane as he saw her hands seeping with darkness; she seemed to be preparing an attack.

Jack wanted to try out some ideas.

First, he started to vibrate his entire body and kept the energy in his body. He did so easily enough, his powers coming to him like he was born with them and didn't just gain them. He kept storing the movement of his cells and turning it into potential energy.

To prepare for his powers, Jack struggled to find any kind of material that could help him but one day he saw his sister, May, watching something on her laptop. He later found out that it was Anime, something particularly popular a decade and before ago but soon lost it's appeal when people could enact what characters in said anime could do and more.

People were more interested in real-life Espers opposed to fake ones in an anime.

But Jack came to a realization; what better research materials were there when compared to Anime where the possibility of powers beyond what a human could imagine was fully explored.

This specific technique was something he'd learned from a character in Medaka Box. The technique was called Kurokami Phantom and while Jack couldn't exactly replicate the technique he could still use it as a basic movement technique. He didn't prepare exactly how the character did but he used the same principle of speed accumulation.

He kept collecting the potential energy because there didn't seem to be a limit just yet, only a limit on how quickly he could store it.

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The girl opposite him seemed to be ready as she suddenly attacked, sending tentacles of darkness whipping at him like two venomous snakes. Jack quickly sent the potential energy to his feet and blasted off from where he was, past the tentacles and in front of Akane.

Akane seemed shocked by his speed and so did all the other girls outside of the barrier. Even May who was watching from afar just in case something bad happened was shocked at her little brother's speed.

Just as quickly as he got there, he stopped in front of Akane as if the laws of physics didn't apply to him.

Jack quickly threw a punch into Akane's stomach, his hard and dense fist full of potential energy that he dispersed as he made contact with her which added even more devastating power to an already brutal punch.

Akane was thrown back as she let out a harsh yell of pain before colliding with the ground just before she hit the barrier in front of the surprised group of girls.

Mikasa looked at Jack with a slightly manic look in her eye. "Oh? My little bro's already so strong. Aiko, I guess you can go and have your fun." Mikasa seemed to be like a cat with a mouse in front of it; the same kind of predatory coldness came across to Jack and it sent a shiver down his spine.

Aiko jumped up on the seat she was sitting in, with the same excitement as a kid on Christmas. She walked to and through the barrier and then threw Akane out of the barrier with a flick of her wrist.

As Aiko looked at Jack, she had a similar kind of gaze as his sister but Aiko's gaze wasn't cold, it was passionate.

"I promise to go easy on you, Jack-chan~"

Saying this in her usual playful tone, Aiko rushed at Jack with surprising speed and Jack felt some kind of restraint on his arms and legs.

He could still move but for some reason, he knew he couldn't use his movement art again, as the air around him was his own little cage and the restraints on his limbs were the chains connected to the cage.

Jack realized he'd have to use his other power, he felt the energy in all his cells which were passively improving them and slowly making them better and stronger. This was Biomass Energy, it could be used to Augment, Change and Permanently Evolve the body to a higher level. And Jack was about to just that.

Jack told each little bit of Energy in each of his cells to make the cell stronger, more durable and perform its job better.

Jack felt his muscles bulge a little and his bones creak slightly before his skin tightened around his body like a protective shield. Looking at his skin, Jack was slightly confused as it looked slightly metallic while keeping its pliability.

'Biomass Energy is pretty overpowered, huh? I don't have any disadvantages even after giving such a vague description of what I wanted.'

By now, Aiko was in front of Jack and swinging her fist at his face.

Now that he saw it, Aiko's movements she seemed quite slow. Not as slow as something like slow motion or bullet time slow but more like an ordinary person swinging their fist instead of an Esper with her power augmenting her physical abilities.

Jack took a step forward, leaning his body to the side to let the fist harmlessly wave past him. Aiko's eyes widened and her speed suddenly increased immensely as she backed away. But Jack wouldn't let her retreat too easily.

Shooting off after her, Jack used another one of Biomass Manipulation's sub-abilities, Body Supremacy, and took control over all of his bodies movements and made them as efficient as possible meaning he spent less energy and made more ground at the same time.

He suddenly turned into a blur surprising Aiko who thought her Telekinetic Prison would stop his Vibration-Based Ability from allowing him to blast forward again.

Sadly for her, she made the prison to purely deal with his Vibration and not his own physical energy so he could still move as long as he didn't use Vibration Manipulation to do so.

Jack soon caught up to her, his efficient movements seemingly inhuman as he seemed to be unrestricted by any outside factor. Jack sent a kick towards her face at blistering speed.

Aiko saw the kick and ducked under it before going to attack but to her surprise, Jack used his momentum from the other kick to follow through with a heel-kick also aimed at her head. Obviously not expecting such a fluid follow-up, Aiko could only throw her arms up in the shape of an 'X' to block the kick.

There was an audible boom as Jack's heel made contact with some kind of invisible armor on Aiko's arms.

Aiko was thrown back a few meters, visibly wincing from the blow she'd just blocked. Her feet were slightly buried in the dirt below her as the force from the kick was just that strong and the cracks behind her feet showed where she used a telekinetic construct to stop herself.

Jack started slowly walking towards her as he willed the Bio-Energy, as he was starting to call it, to amp up it's strengthening of his body.

Aiko looked at Jack with even more passion in her eyes. "As expected of Jack-chan, you're so strong~" she seemed a bit shaken but she didn't show any fear instead she looked happy about something. Jack didn't know if it was because he was still weaker than her or because of some other weird reason.

The veins in Jack's body started to bulge as the Bio-Energy started to enhance him further and on Jack's skin, red lines were slightly glowing above where his veins were.

Aiko's breath was taken away as she saw Jack walking towards her. He seemed to radiate an aura of the apex, Evolution's Favored person who was below none and along with this aura, he seemed to emit strength, absurd amounts of it.

Even Mikasa looked at him a bit more seriously, her little brother showing power above what she thought was possible for newly awakened Esper.

Suddenly, Jack stopped and released the augment he'd put on himself. Weirdly, he found that his body was still much stronger than it was before.

'I better be careful when I mess around with Bio-Energy, seems some of the effects are permanent.'

Jack put his hands up in mock surrender. "Ahh~ I give up. Aiko-nee was too powerful for me and I got what I wanted anyway." his voice seemed cheery and happy but Mikasa could feel there was something more to it that she couldn't perceive.

"What did you want, Jack?" Mikasa's cold voice was full of curiosity as she looked at her brother.

"Oh, I only wanted to know my limits." Jack innocently smiled at her before turning around. Mikasa sighed and waved her hand to signal Fumiko to release the barrier and let Jack out. Jack walked in an incredibly carefree manner as he went back into the house, followed closely by his quiet older sister, May.