Ok u asked for it
240 is the little boy that J saved. If I recall correctly, 240 and his parents were found under rubble but only 240 was alive (barely). J found 240, saved him, and got him treatment. 240 got attached to J (as you'd expect) because J always came to visit him. They were close and both treasured each other. 240 was blind for a while and covered in bandages because he was basically almost melted to death by the poison that killed his parents under that rubble, hence his poison theme. But J let 240 touch his face n shit when 240 was blind, which is something J never does because he never takes off his mask unless he's alone. The female doctor in the hospital who was in charge of 240's care was a secret Prometheus agent. When J left to take care of that big rift, 240 was left behind without knowing when tf J would come back or if he'd come back. Lil bro was literally just waiting for J this whole time. Prometheus was experimenting on 240 n shit and injecting vile shit into him to trigger an awakening. He was basically tortured and shit. He awakened as a poison user and like melted the whole place down until the guys at the bureau found him and took him in. 240 was devastated because J disappeared but only agree to come due to the slight chance that he'd be able to meet J again. Everything he did from growing up to starting Pado to dungeon clearing has been to meet J again. When J finds all of this out and realizes who 240 is, he literally breaks down and so did I. It's a very emotional scene that destroys the soul bro. I can't wait for it to be illustrated because the way 240's smile is described in that chapter is really sad but hopeful. Ugh. I'm gonna cry thinking about it again.

I'm just sayin. Yall are NOT gonna be ready when J finds out who 240 really is. But u didn't hear it from me O_o