Your name is Kira in this cuz I'm not writing Y/n a thousand times. You're 16 he's 16. I'm pretty sure that's how old he is in the anime anyway, not sure. Your technique is Dismantle and Cleave. Also, in this, you're Sukuna's lost kid. he doesn't know you exist and you keep it a secret from others. so they don't.. get scared or whatever.