The Eerie Invaded, and I Was Struck from the Human Register

I've had the same dream since I was little. It is hazy, but in it, people from ancient times are holding a sacrificial ceremony. They wear strange clothes and pale masks, performing a dance to offer up to the gods. And I stand at the center of the altar, the most treasured sacrifice of all. [This work comes with... complex worldbuilding + no romance + secret identities + a newbie author, and more buffs]