
Yeah, all the "summoners" you see? They’re the real dead people. The so-called "heroes" aren't really dead. I can't remember exactly what state they’re in, but the summoners are already dead outside of the simulation. That’s why it's so ironic to see the heroes in coffins while the summoners are the ones who’ve already actually died.
The MC was isekai’d there because he essentially serves as a "battery" to power the world. Before the MC, Hamel had bought multiple people who had already died in their original worlds, only for them to die again in this one once they reached the end of the world. This process helped fuel the simulation.
But here’s the twist: the MC is different. For some reason, he has an unusually high amount of holy energy (if I remember correctly), which is why he can summon Shane, the hero and "ender of the world." This holy energy also explains why Shane is able to wield the holy sword we see him holding at the beginning of the story. Only those worthy can hold it, and both the MC and Shane are able to. This plays a huge role in how they ultimately create a new world at the end.
Men, I really luv the ending of this. So many things before the big reveal to the point that it's very confusing, but, all that confusion is worth it because of the ending.
The flow of the story is very similar to building a puzzle. Every chapter gives you one piece of information that you have to fit into the incomplete image. And only by putting in the very last piece will everything fall into place.
It's a very happy and fulfilling ending as well.