Originally Posted by
Some Jerk
So the reset button is indeed in play. At least they found a way to make it not corny... yet. Illya going back in time spiritually rather than physically puts a drastic limit on the things she can change.
We can probably guesstimate based on the bits of self-narration that Illya has given in previous chapters. The last one I recall is Chapter 45 (or at least MangaDex says it's Chapter 45) when she's talking about how "everyone sort of felt that the last battle was upon them". Unless there's an earlier self-narration I'm not remembering (please correct me if so), it's a safe assumption that Illya is going back to the night before everyone sets out for the final battle. I'm betting her audience is herself, but I'd like it to be Pandora with a hint that she got the idea from the end of this chapter.