The Ten Days to the End, dating shows, Ultraman, Slay the Gods, Harry Potter, The Walking Dead, From, Marvel, and more. The order is undecided, and other worlds are still to be determined.
Not every protagonist gets sacrificed.
First world: The East Palace!
The protagonist gets sacrificed, and the drop rate goes through the roof! [The East Palace is a brief transition; it ends after just a few chapters.]
One and only protagonist, female-to-male transition, with women in the story. Everyone is heterosexual in terms of gender, and there is no fixed pairing.
