I'm surprised to see just how many people are aroused by Marche, I definitely thought she was cute but dang, I think she has the most R18 of all the 5th anniversary reveal umas.
the more innocent they are, the more satisfying it feels to taint them
I've never understood the food of doom trope. Like, how do you not sample your own food to make sure it doesn't taste awful? And even if it does taste good to you, it may not appeal to others. Those are the most essential rules one needs to know and follow when it comes to cooking.
In Frieren demons are a humanoid species that evolved from magic beasts. They are not from Hell, they are not the disciples of the Anti Christ or Satan or Lucifer or The Devil, thus the cross does jack all.
Neither harming the devil, nor protecting them from the white haired Elf.