The best way I can compare it to is Magica Madoka, meaning he might’ve already tried it. There were a lot of bodies beneath them so there’s no telling how long he’s been resetting time.
Guess he's just testing the waters? But I do get what you mean. I think he hasn't really recovered from all that stuff happening to him, so all he can do at the moment is to just give up and see what happens. Like imagine seeing your father get murdered AGAIN just like that in front of your eyes while you're lying helplessly, and it's right after witnessing a whole ass slaughter scene... it's kind of impossible to process all that in no time
Why's he trying to die. That's dumb. He can still kill Guwon but without letting the townsppl make all the stupid mistakes they made the first time.