Ourty found/figured out the original body was a sacrifice to the demon king, possibly made the connection that she had an abrupt personality change when the hero(ine) 'died', and that has something to do with his plans is my bet.
@cloverdit
same thing literally happened to me, i usually go to the comment section after a chapter and i was like sucks to be you man before i realized i too had unknowingly reached the end.