In a way I think it fits. With her obsession, she's finally achieved her goal even if it wasn't how exactly she wanted it. At this point she may just want to go live peacefully. I don't think it's out of fear. She seems exhausted emotionally to me. Just my 2 cents though. I would love to know the authors reasoning
Nah she just realized how she messed up making dylan a tryant, a tryant she raised that that wouldn't be obsessed with her, just only a tryant in her hands, to be honest she doesn't know he whould go beyond just to please her and she kinda just realized that, i think that's the reason why she's running away

Running away doesn't match her character to be honest she was sold in the story cold manipulative, strong and have a goal but she suddenly choose running away when her wish came true it would suited her more just bluntly abundance, she used dylan got what she want and now leaving because there's no one that mean something to her, but running it give the impression of fear and for someone who slay monsters easily its out of her personality. Just my thoughts