Age: 13
There is a theory that school textbooks avoid mentioning: Somatic Determinism.
Society sells us the idea that Quirks are tools, like a hammer or a flashlight, that we keep in our pockets until we decide to use them. But biology doesn't work that way. A hammer doesn't alter your brain chemistry. A Quirk does.
Think about it. Endeavor isn't an intense and aggressive guy just because he's a jerk (although that helps); he is that way because his basal body temperature is higher than that of a normal human, which keeps his metabolism and testosterone levels in a perpetual state of "fight or flight."
I am no exception. My sweat is nitroglycerin. To produce it, my body needs to maintain slightly elevated blood pressure. My neurotransmitters are bathed in compounds that stimulate aggression and reactivity. I'm not always angry because I want to be; I'm angry because my biology demands I be ready to detonate. It is a constant itch beneath the skin.
If I didn't train, if I didn't blow things up regularly, I'd probably be punching walls or screaming at my mother about the color of the curtains.
We are slaves to our genetics. And society judges us for instincts we didn't choose.
"What was I thinking about...?" I muttered, shaking my head to clear the fog of academic thoughts.
Ah, right. Walking.
I had sent Izuku home early with the excuse that I needed to study, but the truth was I needed to burn off mental energy. The night was humid and sticky, and I was walking down a back street near the train station, an area of closed bars and flickering neon lights.
That was when I heard the sob.
It wasn't a cry of sadness. It was the sound of someone hyperventilating, fighting against their own biology. The sound of an animal cornered by its own instinct.
I stopped in front of the gap between two vending machines.
My common sense (what little I had left) told me to keep walking. I'm not a vigilante. I don't have a license yet. But my previous reflection resonated in my brain. We are slaves to our genetics.
I approached slowly.
"Hey."
The figure tensed violently. It was a girl my age, maybe a year older. She wore a middle school uniform I didn't recognize, dirty at the knees. Her blonde hair was messy, two buns that looked like they were unraveling in a nervous breakdown.
She raised her head.
Her yellow eyes, slanted and cat-like, locked onto mine. They were bloodshot, pupils dilated to the max, devouring the scant street light. There was a cheap Swiss Army knife in her right hand, and a small cut on her own left forearm.
She was licking her own blood.
Upon seeing me, she quickly hid her arm and forced a smile. A terrifying smile, too wide, that didn't reach her frantic eyes.
"Hi, hi!" Her voice was high-pitched, brittle, on the edge of hysteria. "I was just... uh... I fell. Yeah. I got a scratch. I'm so clumsy!"
She was shaking. Sweating cold. The smell of iron and anguish was palpable.
"Stop pretending," I said, my tone flat and bored. I shoved my hands in my pockets. "You're going through withdrawal."
The girl's smile faltered, trembling at the corners.
"W-what? No... I don't do drugs, that's bad, my parents say that..."
"I'm not talking about drugs, blondie. I'm talking about iron. Hemoglobin." I took a step forward, invading her personal space with calculated arrogance. I needed to break her defense barrier. "You smell like blood, but not with fear. You smell with hunger."
The girl backed away until her spine hit the soda machine with a metallic clank. The knife trembled in her hand.
"Go away..." she whispered, her "normal girl" mask shattering into a thousand pieces. "Go away or... I'll cut you. I want to see... I want to see if you're red inside... You look pretty... I want to be you..."
It was a potential villain's speech. Any average hero would see a threat. I saw the same thing I see in the mirror: a defective biology screaming to be regulated.
"Your Quirk. What does it do?" I asked, ignoring the stabbing threat.
"GO AWAY!" she screamed, slashing clumsily at the air with the knife.
I didn't even flinch. I didn't even take my hands out of my pockets.
"Transformation, right?" I deduced. "You probably need to ingest DNA to activate it. Blood is the easiest vector."
She froze, panting, knife in mid-air.
"How...?"
"It's basic science." I sighed, as if explaining why the sky is blue. "Your body doesn't produce a certain enzyme or protein necessary for your metabolism, and you seek it in external sources. Society calls you a monster, your parents tell you to repress it, and your brain is frying because you're fighting a biological survival instinct. You think it's love, or desire, but it's just mismanaged hunger."
I stepped closer to her. We were half a meter apart.
"You're not crazy," I said, lowering my voice, looking directly into those chaotic eyes. "You're malnourished."
The girl blinked. A solitary tear, heavy with grime, rolled down her cheek.
"Mal... nourished?"
"Yes. And repressing hunger only means that when you finally eat, you'll binge and kill someone." I took my right hand out of my pocket. With a quick, precise movement, I bit the pad of my thumb. The tough skin broke and a drop of dark red blood welled up. "Drink."
She looked at my finger as if it were the answer to all the questions in the universe. Her pupils contracted and dilated rhythmically.
"C-can I?" she asked with a trembling voice, as if expecting it to be a trap.
"It's a clinical test. Do it before it coagulates."
She lunged. She didn't bite me. She grabbed my hand with hers, which were freezing, and licked the drop of blood with almost religious reverence. Her tongue was rough, like a cat's.
I waited, counting the seconds. One, two, three...
The shaking in her hands ceased. Her breathing calmed. The fog of madness in her eyes cleared, revealing a sharp and curious intelligence behind it.
She let go of my hand, looking at me with awe, savoring the residue.
"It tastes... it tastes like sparks. And spicy caramel," she whispered. Then, her cheeks blushed violently. "It's delicious! You're delicious!"
"It's nitroglycerin in my bloodstream," I corrected, wiping my finger on my pants. "Now, listen closely. Your brain confuses the need for blood with 'love' because both signals occur in the limbic system. You are not a psychopath. You just have a special diet that no one bothered to explain to you."
She looked at me with her mouth open. For the first time in her life, someone hadn't told her to "be normal." Someone had validated her existence with facts.
"Who... who are you?" she asked.
"Bakugou Katsuki. Future Number One Hero."
She smiled. This time, it was a real smile. A bit crooked, with fangs showing, but genuine.
"I'm Toga. Himiko Toga."
"Good, Toga." I turned around. "Get up. You can't keep licking your own wounds in an alley."
"Where are you going?" she asked, taking a step toward me, latching onto my presence like a lifeline.
"I'm going to buy raw meat. Liver, probably." I glanced at her sideways. "And you're coming with me. We're going to figure out how much you need to consume daily so you don't have to attack people in the street."
Toga's eyes shone with a new intensity. It wasn't just gratitude. It was instant devotion.
"Yes! Yes, Katsuki-kun!"
She came closer and, with alarming naturalness, linked her arm with mine.
"You're my best friend now!" she declared, resting her head on my shoulder.
I tensed. My solitary instinct screamed, but my logic silenced it.
"Don't get excited, vampire. You're a test subject."
"Hee hee! Whatever you say, Katsuki-kun!"
As we walked toward the convenience store, with Toga clinging to my arm and humming a disconcertingly happy song, I thought about the implications.
I had just adopted a future S-rank villain. Izuku was going to have a panic attack when I introduced her ("Kacchan, bring a knife!", "It's to cut the ham, Deku, calm down").
But feeling the tremor in Toga's arm completely disappear, I knew it was the right decision. The system would have locked her up for being what her biology dictated her to be. I was going to stabilize her.
Because if anyone understands what it's like to have a body that demands violence, it's me.