Comment by Tinkletoe on Dead man Switch - Chapter 45

@Spinxyq ok so from what i understand (and a personal theory) the whole loop thingy started when black haired guy wished for hohyun (mc) to not die. I think it was a manifestation that turned into a chance to save the mc even tho he didn't know it was himself who wished for it, he thought hohyun was the catalyst of the time loop and would devote the entire regression into saving him only for hohyun to die more than 20 times.

My guess is that he needs to be the one to kill hohyun in order to stop the time loop from repeating.