If you're gonna bother to write such a contrived "reveal", I would at least expect the MC to be responsible for whatever happened, this isn't the way to do it. What, am I supposed to feel like MC isn't justified in his revenge, cause he played a stupid choking game ONCE and it drove the other kid insane? No, he was clearly already odd
"What a weird game... Let's go"
"Choke me daddy"
"Huh...?"
"I see, you can't be my daddy ever again"
"What...?!"
Takes his hands and puts them on his own neck
"Daddy's choking me to death"
"What the fuck is happening??"
"COFF KOFF URGH ARGH DADDY HOLY SHIT!! DEATH IS AMAZINGGG!!!!
Kills nearby baby
"Why??!?!?"
Like, at least have the MC have a bit of a screwed up side to himself, that lead the antagonist to be born, and he forgot about it since it makes him as guilty, this is just the antagonist being a little freak like always, and strong arming MC into something that wasn't done with bad intentions, nor lead to any, and it woke up his psychosis?? At least have him choking into fainting, and not just slightly blacking out.
I'm half hoping this is leading into a situation where he comes out of the VR machine, antagonist smugly asks "did you remember?" and he just shoots him in the fucking face without changing expressions, but something that funny is above the author's paygrade I think.