3. CRUMBLE
All for One. A quirk that could take and delegate the quirks of others. In his own opinion, there was no better quirk for him.
His younger brother, One for All. Despite being named in similarity to his, it was a completely useless quirk. A quirk that could only pass itself on throughout the years.
While All for One stockpiled on his own variety of quirks, giving them out was another matter completely. There was a set of conditions that he could not yet figure out. Thus far, he has never been able to give a quirk out to someone without breaking them, mentally, physically and emotionally, rendering them a doll that only obeyed orders.
Meanwhile, One for All had found its use. As it passed itself on, it merged with any quirk that the users have had, and passed them on as well. It came across a strength-enhancing quirk, and that was where it eventually led to All Might, the Symbol of Peace.
All for One, having conjured up many obedient dolls, began to lose hope in ever creating a perfect Entity. Perhaps, this was the drawback of the quirk, and it was not fixable.
But then one day, All for One came across one boy. A quirkless boy that screamed to the heavens, cursed at the strong and cried for the impartiality of the world. A boy who laughed like a lunatic as he drove himself to madness and threw himself off the roof.
All for One realized something. If giving someone a quirk meant that they would become broken and disfigured, what would happen to a boy that was already broken?
And so on that day, as the boy fell from the roof, a black mist shrouded over him, enveloped him, and consumed the boy. When the black mist faded, the boy had gone with it.
No one noticed the boy whisked away in mid air. No one looked over to this side of the building, which faced away from the roads. Kurogiri had brought the boy to their hideout, where the experiment began.
Shigaraki had looked through the boy's bag in mild curiosity and found what seemed like an extremely detailed observation journal of the heroes. According to the title, he had twelve more of these! This boy had the talent to become a great fighter. But his efforts were meaningless if he hadn't the strength and abilities to compromise his intelligence.
But the villains needed none of that. Strength? Skills? What were they in the face of strong tactics and false plans? What were they in the face of an information leak? Both sides needed all the smarts and knowledge they could have.
If this boy was weak, the villains could just protect him. If this boy was with them... He would be a great addition to their arsenal. They would know the heroes' abilities and possible plans. They would know ways to counterattack them.
This boy may have the potential to become a hero, but he had a much, much greater potential to be a villain.
And so the experiment began.
Hyperthymesia. A quirk that gives the user hyper memory. Photographic memory. The ability to never forget something they've seen. The syndrome of remembering every detail of their lives.
Coupled with Deku's observational abilities, he could deduce a lot of information from just seeing someone in action once.
And Deku, realizing that fact, used his power well.
"Sensei," Deku calls excitedly, a happy grin on his face as he runs around the secret base looking for said man, "Senseeiiiii!"
Shigaraki Tomura gives him a light knock on the head. "What? you're noisy."
"Shigaki! Have you seen Sensei?" Deku asks, smiling cheekily as he mumbles a half-hearted sorry I was noisy. He had taken to calling Shigaraki 'Shigaki' instantly, and Shigaraki hadn't the chance to correct it before it was set in stone.
"Sensei is resting." Shigaraki answers the boy, "What did you need him for?"
Deku shows the older man the dozen or more worksheets in his hand. "I'm done with the work!" he says, "And Sensei told me to get more from him when I finish."
Shigaraki took the small stack of papers and read through the first one. It was a classic school math test, nothing out of the ordinary. The two had given these to the boy to train him in his quirk. As for why they had these around, one of their minions were in junior high and needed their homework done. Killing two birds with one stone, that girl had the cheek to say.
"I'm also done with English, Japanese, Biology, Chemistry and-"
"Yeah, yeah," Shigaraki dismissed his listing, not wanting to know how many subjects there were as he had at least a dozen in his hands already, "Go read a book or something. I'll give this to Sensei."
"Yess~!" Deku sang childishly, heading towards the bar where Kurogiri hung around. Maybe that guy had a few interesting stories to tell.
"Mt. Lady?" Deku asked.
"A new hero." Kurogiri said, producing a picture from his pocket and handing it to the boy, "What do you make of her?" he asked.
Deku returned the image. "A simple and straightforward, giantification quirk." he began, "A great quirk, but she seems to focus more on fanservice than anything. If not careful, she could very well destroy more of the town than the villain...if that happened would the villain be blamed for the damages or would the society just go meh about it? but that would depend on whether she can fully control her quirk as well. She depends mostly on her size to attack, so her physical strength does not need as much focus as her skills and maneuverability in fighting in busy cities-"
"That's enough, Deku." Kurogiri interrupts, taken aback, "You know a lot."
"Yeah. I saw her debut." Deku answered simply, "It's written on the twelfth page of My Hero Analysis book 13."
Sometimes, Kurogiri wishes Deku didn't have such a frightening memory. (Also, all that mumbling is a little... disturbing.) He sighed, handing the frizzly-haired boy a glass of juice.
"Oh, thanks, Girigiri-san!"
"It's Kurogiri."
"Anyway, are we really planning on taking All Might down?" Deku changed the subject, much to Kurogiri's dismay, but his bright smile wasn't something someone could deny.
"Yeah." Kurogiri said, wiping down a cup, "That's why we got you."
"Yay~!" Deku laughed, "Sensei hasn't told me exactly what to do yet, though." he slumped on the table lazily, "He toldme to take a week or two to get used to my new quirk."
Ah, so that's why. Kurogiri had been asked to gather homework that would replace the year Deku would miss in school. Deku had been surprised the first time he flipped through a high school textbook. Despite not having learned it before in school, he instantly knew how to answer all the question in the workbook. In three days' time, Deku had gone through every subject at the high-school level.
He had then began to rewrite the other twelve hero notebooks he could no longer retrieve. He wrote everything done without reference or breaks, even the little notes and sketches he had scribbled on during his fanboy phase. In a week's time, he was all ready and now trying to explore the various uses of his own quirk.
"Are you doing well with your quirk?" Kurogiri asked.
"I love it!" Deku beamed, "It's so fun!" he laughed, "I know everything! But..."
"But?"
"I don't know why, but I can't remember my last name." he said, sulking at the table, pouting, "What made him like heroes so much? Why was he so weak? Why was he so scared? I don't really understand a lot of stuff anymore. Why did he cry? Why did he get mad? Why did he worry, why was he always so afraid of strong people?"
Hearing that, Kurogiri was stricken with a little realization. Every quirk has a drawback, so this quirk, Hyperthymesia, must have one too.
"They're called emotions." Kurogiri told him, keeping a calm and collected manner, "beign happy; being sad; being afraid; being worried...they're all emotions a human being should have."
Deku listen intently, interested. "I see..." he mumbled, a little smile gracing his face, but didn't reach his eyes, "Sensei created me, so I'm probably not a normal human being anymore. I'm an artificial being? An experiment? A Noumu- And I guess I don't need 'human emotions' anymore."
A Noumu. They had thought that Deku was a miraculous success, a sentient Noumu. But perhaps, he wasn't as sane and receptive as they thought. His mind was deteriorating from this quirk. One day, Deku might become a voiceless doll that only knows to obey orders.
Extra:
When Kurogiri first met Deku, Kurogiri had the impression that this kid didn't know where he was at. He was smiling sweetly, innocently and absolutely adorably, looking pure and untainted as a newborn baby.
"I'm Deku!" he said perkily, in a way that seemed to charm the adult male. He held out a hand in offering of a handshake.
It took the adult male a moment to realize it was his cue. "Oh-" he wiped his hands dry and took the boy's hand in his, "I'm Kurogiri."
"Girigiri?" the boy had asked, his head tilting to the side, "That's a weird name."
"It's Kurogiri." the man had to correct.
"Girigiri."
"Ku-ro-gi-ri."
"Giri-giri-giri?"
"Are you doing this on purpose?"
"Girigiri!"
"Shigaraki-"
"Give up." the male said. "Just give in."