I haven’t seen enough of Letio to confirm but I feel like since he’s had quite an isolated upbringing his view of the world is quite immature. He defines what is it good and what is evil based on his own morality, his relationship with a person and their usefulness/actions towards him or his loved ones. He doesn’t leave room for thought about the complex nature of humans and how people’s actions are not always black or white and that there’s always going to be a morally grey area, very similar to the way a child thinks. He already labelled the crown Prince as a bad person because he’s obstructing his relationship with Selena so him being the catalyst for the duel and ultimately Selena’s injury was the justification he was looking for. Now Letio has no reason to hide his hatred so he’s quick to curse him out and voice his distain. I can see why everyone doesn’t like him currently but personally I don’t think we’ve see enough of his personality to be push him into the category of a ‘creep’ or ‘yandere’ because, as I mentioned before, he’s quite childish so the way he expresses his love is also in a childish manner; possessive and smothering. Ultimately all he wants is the best for Selena so his intentions are right but the way he’s executing it is wrong. Hopefully we see some character development from him as Selena continues to teach him boundaries like she has been and maybe even provide a new perspective of morality for him. Sorry for the long ass comment, I didn’t think I would end up typing this much but I didn’t like how everyone was so quick to judge him.