.
the priest said that because he don't want the fl to return to her world which is pretty much selfish. the FL will eventually return to her original world which requires someone to kill her. someone who doesn't harbor any feelings for her and guess what? the normal knight ended her life for her and burned her body so that the 3 idiots cannot revive her. that's how obsessive the 3 are. also, the story doesn't end after she went back to her original world, she met the ml(which is the normal knight) in the original world(idk how it happens though). The novel fl dies, too. and the 3 idiots left with no choice but to accept the facts that the fl don't have either of them to end up with her since she wanted to kill herself or someone to kill her. so yeah, this story is tragic, sad, and somehow romantic(the ending).(づ ̄ ³ ̄)づლ(´ڡ`ლ)
spoiler
what the fl said was true, the ml's father really love him. he cannot show affection since there's a faction (i think belong to the novel's ml) who are monitoring his every moves and he cannot recklessly shows affection(it might been used against him). also the novel's ml, our ml and the fl are the reincarnation of the story mentioned (i think it's about the goddess chuchu and human chuchu) so basically, the reason why the fl got the power and the ml got the curse. so yeah
not this fucking bitch. you know why? cuz the empress mother is the previous grand sorceress and based on it, the power of the previous grand sorceress will be passed down to the relative(specifically, the child of the grand sorceress) since they don't know if the previous grand sorceress has a heiress or child, they assumed that this bitch is the grand sorceress.