first chapter isn't the first timeline, its the second timeline after the event of chapter 8. in the first timeline enemy princess (gonna call her amy, cuz why not) didn't succeed because she can't get close to the king hench why she cursed the princess (this one I call mira) instead. reason is because the hero doesn't exist so the amy have no chance to even get close to the king. the curse never got explained but what if the curse on hero is just another version of curse on mira?? the curse specifically say "trapped" which unusual for immortality curse, so mira most likely trapped in time itself unable to got forward or backward. she is forced to live her life again and again until her resentment became another curse, directed toward the kingdom and amy in form of demon king. now because of the previous time curse, the demon king curse got sent back in time. making it the second timeline where a hero is needed, because of this the time curse didn't fully activate, only rewinding the time and mira forgot about everything. ch 2 is where the curse activate again and since mira loved the hero it got passed on. continue the story and now the knight kept repeating his life, this presumably make the time curse inside mira active again. basically the mira in ch6 is the one from ch8, the curse made her remember everything and she finally got her long awaited revenge in chapter 7 (looking back I can just name then master and princess smh)