fine, I'll spoil it.
Asellus is magically transformed into dykery through a blood transfusion from the king of mystics. his sexual preferences exist in the blood. the ending of her scenario depends on your choices; you can embrace her sexual depravity and turn her into a mystical tyrant, or you can choose the "human" ending and she has a reasonable hetero relationship with the other female characters.
the yuri is if you choose to make her evil. it's an amusing twist, and it pissed off some Twitter homos when the game was re-released a couple years ago.
