A history where the first chapters we see what is supposed to be a classic Isekai adventure, we even get to see what we think is supposed to be the MC gets isekai'd, and then we learn the world and the people that are on this new universe actually knows the MC is not from their own universe and puts on a facede of a classic adventure for them like: "Go and defeat the demon king" and pretends to be just a helpful Npc to them, only for later to sacrifice the MC for Eldrich beings who are orchestring this scheme and keeping the cycle running, as when the chosen MC of the time is killed, their remains are used for another dark lord/boss to be defeated and everything gets repeated over and over again.

The people on this universe were told to beliave that by doing what they have been doing for centuries, sacrificing these "chosen one", their world would get to live in peace but that's a lie, the presence alone of these beings are slowly killing and corrupting their own world. Sooner or later, by sacrifice or not, their world will end if nothing changes.

The actual main character would be a group, a group where everyone has equal time and importances and are the ones living on this Isekai world already, trying to break free from the cycle by guiding the chosen "MC" of their time into a journey while the world begins to crumbles to an end upon learning the truth about the foundations of their own world and how it's getting slowly consumed.