
Maybe that white-haired dude has some sort of healing ability? While the one who is manipulating the time is a different person. Maybe, I don’t know..

Or maybe he is the same person as the one with time manipulation. I think since he was only focusing on a single object/person that makes it look like a regeneration ability but in actuality he is turning back time on that one single object/target only. Whereas the reason why the whole class was turned back in time after the villain killed them is because he may have been unconsciously releasing his power each time he felt the "scary presence". Remember how he was able to feel the villain's presence each time he got close?
The MC is low-key kinda like Killua but more chaotic and psychotic.
But killua cares about someone he doesn't (〜 ̄△ ̄)〜
Killua is biased tho and usually only towards Gon and through people that he’s okay with
╮( ̄▽ ̄)╭