Some random musings. So the Potag (by which I'm referring to the person from the "real" world that took over Evie) get's sent back in time by Future-Elsa. The situation, such as it is, is that an unstoppable pack of demons and beasts is barreling down on this village, and FE implies that it will lead to Protag's death. We can assume, though we don't know for sure that this is the timeline that FE is from. If it is, she seems to have lived in that timeline for awhile, seeing as how she's a bit older than Elsa is at that time. Presumably, with the help of Linda, FE learns time travel magic in order to save Protag.
Further more, in the "present", there is a new demon lord. Now if I understood that earlier exposition, isn't it an aspect of the curse that allows the demon lord to be reborn? If so, something must have happened either to the fragment of the curse that is now in Elsa (and we can assume is also there in the present timeline) or to the main seal (i.e. the corpse of the Sage). I think it's safe to say that either way, Olivia is playing some role in the demon attack in the "present" assuming Olivia isn't actually just Dahlia in disguise.
What's really important about this arc, is that it isn't just a flashback to show us as readers what happened, but to show the Protag what happened as well. We still don't know at what point in Evie's life the Protag took over. This whole trip has probably given the Protag far more context on Evie's life than she would have had just from the game info.
I gotta say, I was not expecting this kind of depth in a webcomic called "Please Bully Me, Miss Villainess!" lmao but I'm absolutely here for it.