I was twelve years and four months old the first time I killed someone.
I want to write that sentence accurately, which means not softening it and not dramatizing it, both of which would be dishonest in different directions. It happened. I made a choice. The choice had a consequence that was permanent and irreversible and I have thought about it carefully many times since and I have arrived at the same conclusion each time, which is that I would make the same choice again.
Here is what happened.
I had been on the roof, late, later than usual because the summer heat made the building stuffy and the roof was the only place where the air moved. Past midnight. The city doing its night version of itself, quieter, different quality of light, the particular emptiness of streets that belong to a different population after dark.
I heard it before I saw it. Two streets over, sounds that resolved quickly and unmistakably into someone being hurt. Not an argument. The specific acoustics of violence, which are different from the acoustics of anger and which I had learned to distinguish from two years of sitting on this roof paying attention.
I should have stayed on the roof.
I was twelve years old with cursed energy I had been training for years and a deep structural rage about exactly this kind of thing, and I had been watching this city from this roof for two months thinking about the gap between what I was and what was needed, and I did not stay on the roof.
I went down the fire escape on the east side, which I had also located and tested. Thirty seconds to the street. Another forty to the source of the sound.
The alley was narrow and poorly lit and contained three people. Two standing, one on the ground. The one on the ground was a woman, probably mid-thirties, not moving in a way that suggested consciousness. One of the standing figures had a knife. The other was going through her bag with the casual efficiency of someone who had done this before and intended to be done with it quickly.
Neither of them heard me come in because I was moving with full reinforcement and I had spent enough time practicing silent movement on the orphanage roof that I could cross pebbled surfaces without making meaningful sound.
The one with the knife saw me at the last moment. He was fast. His quirk, which I assessed in the half-second before he moved, appeared to give him elongated arms with the reach and snap of something elastic, because his arm came at me from a distance that should not have been available to him and the knife was at the end of it.
I stepped inside the reach and put my elbow into his throat with reinforced force and he went down and stayed down. That part was clean. That part was straightforward. He hit the ground and the knife skittered on the alley floor and I registered all of that in the background because the second one had turned around from the bag.
He was larger. His quirk manifested visibly, his skin had hardened into something like rough stone, the kind of passive defensive quirk that made the person wearing it casual about violence because violence had generally not worked on them before. He looked at me, a kid, twelve years old and lean and standing over his partner, and he did not run.
He came at me instead.
I could have incapacitated him. I have thought about this. I could have targeted the joints, which the stone skin did not appear to extend into fully, or I could have used Dismantle at close range against something unprotected. I had options that did not end where this ended.
What I did was plant my feet and let the energy come up fully, the way it had never fully come up before outside of controlled training, and when he was close enough I cut.
Dismantle, clean, at near-zero range, with every bit of force I had behind it and no hesitation in the intent because he was large and his quirk was defensive and some part of me had already calculated that a half-measure was a risk I did not want to carry.
The energy found the gaps the stone skin left. There were several.
He went down.
He did not get up.
I stood in the alley for a moment that felt longer than it was and looked at what I had done.
The woman on the ground was breathing. I could hear it. Shallow but present. The first man, the elastic-armed one, was also breathing, unconscious, his throat bruised in a way that was going to be significantly painful when he woke up and that I did not feel bad about.
The second man was not breathing.
I noted this. I felt myself note it, felt the part of my brain that was still Ryo Shiba from Earth doing the thing human brains do when they encounter irreversible facts, the slight dislocation, the moment of full comprehension.
Then another part of me, the part that had been sitting in my chest for twelve years getting warmer and larger, settled into something that I can only describe as calm. Not satisfaction, exactly, though I was honest enough to notice that the satisfaction was there at the edge of it. Calm. The calm of something concluded.
I had done it completely and without hesitation and it had worked.
I crouched down and checked the woman's pulse with two fingers against her neck. Strong enough. I straightened up and looked at the alley, at the sight lines, at the light sources. No cameras at this angle. The main street had one but it covered the entrance to the alley, not the interior.
I picked up the knife from the ground with the hem of my shirt and walked to the far end of the alley and dropped it into a drainage grate. Then I went back the way I had come and up the fire escape and onto the roof and sat with my back against the water tower housing and breathed.
I was not shaking. I checked. My hands were steady. The energy was settling back into its resting state with the easy quality of something that had done exactly what it was built to do.
I stayed on the roof for another hour.
What I thought about, in that hour, was not what I had expected to think about.
I had expected guilt. Not because I thought I had done the wrong thing, I did not think that, but because guilt is the standard human response to killing and I was still human enough that its absence would have been worth examining if it had been absent.
It was not exactly absent. There was something in the register of guilt, a recognition of the weight of what had happened, a refusal to treat it as small or routine. I was going to carry this. It was going to be a fact about me permanently. That mattered.
But underneath the weight was something else. The anger that had been accumulating since I was ten years old watching a number update in the wrong direction at the bottom of a news screen. Since I was nine watching Kenta circle a smaller kid. Since I had understood, really understood in the bone-deep way, that this world operated on a system that processed the people who hurt other people through mechanisms that reliably produced more hurt people.
That man had been in that alley, with a knife, with a partner, not for the first time. The woman on the ground was not his first. The elastic-armed one in the courts would hire a lawyer and go through the process and eventually come out of the process and there would be another alley.
There would not be another alley for the second one.
I sat with that and found it straightforward in a way that I examined carefully for self-deception and did not find any.
The thing in my chest was very calm. It did not gloat. It did not push. It sat with me in the dark on the roof and the quality of its presence was the thing I had named agreement.
In the morning I ate breakfast and went to class and wrote a quiz on regional geography that I finished in eleven minutes and spent the remaining time staring at the window thinking about the mechanics of Cleave.
Three days later the news carried a brief item. Woman found injured in alley, recovering. Male companion found deceased at the scene. Incident under investigation. The elastic-armed one had been found by police, also at the scene, and was now in custody.
I read the item once and moved on.
Two weeks after that I started thinking about the vigilante identity in concrete terms rather than theoretical ones. Not because I planned to make a habit of this immediately. I was twelve, my power was real but not yet sufficient for consistent vigilante work, and I had enough foreknowledge to know that the reckless path was the one where I moved before I was ready and drew attention I could not manage yet.
But the door had opened. I had walked through it once, on instinct, and I had come back through it intact and I had come back knowing something about myself that I had theorized but not confirmed.
I was capable of this. Functionally, technically, and in every internal way that mattered.
The form it would eventually take, the identity, the appearance, the deliberate construction of Sukuna as a separate and unconnectable presence, that was future work. Patient work. The kind I was good at.
For now I trained. I pushed Cleave further toward functional. I sat on the roof at night and watched the city and did not go down the fire escape.
But I knew the door was there. And I knew I could open it.
That was enough, for twelve.