I think its more like he doesnt want to die but he knows that if he fails to fulfill his duty as a sacrifice, his family will be the one who will have to pay for it. Rn he knows that mugo has no plans to kills him so he's more anxious not knowing what the head family could do to his family. He probably had forgotten abt this worry while he let himself enjoy his time with mugo but after meeting his brother again, his worries are back and fear is finally sinking in. He probably didnt realise the gravity of this situation until now, thats why he asks mugo to just kill him. After realising that mugo wont kill him, he runs away hoping that atleast wandering around will cause his death.

Bro the more chapters I read the more confused I am?? Wasn’t he bitching that he didn’t want to die the first few chapters than he wanted too, then he didn’t, and now he does but also doesn’t and runs away??