This final feels empty for a good story what could be, I mean, everyone knew what was going to happen to her but literally is the same shit of the first timeline just for the letter or maybe worst! The only thing that he did was being an asshole towards her bc he doesn't want to make an "emotional bond" or some bullshit like that.
He could be nice to her like the first time, do the same things and maybe SPEND MORE TIME WITH HER BEFORE SHE DIES and do not make the confession. Simple like that, if you know that she is gonna die MAKE PROGRESS WITH ANOTHER GIRL/HUMAN BEING OR SOMETHING MAN, and I'm very sure that in the first timeline he could bring back the band like this one if he was honest towards his friends, tells what he said to her, apologies, idk.
Literally 9 chapters of drama shit without sense, this could be more, anyways thanks for the translations guys!