Responses

doesnt arin’s ability work for 30 minutes if she kissed a living thing? their eyes turn red after the impact has been made and will basically worship her. there’s no telling sion is immune since we hadnt seen arin kissing him and the results of it yet. but he does seem to hold arin in a positive light and doesnt mistreat her like the others.
i think Sion (green haired) is also immune to Arin's powers, or at least he loves her enough that with or without Arin manipulating him, he'd do her every bidding. I say this because in the first chapter, we only see three of the brothers with red eyes and confessing their feelings to Arin.
I am not sure tho if his "love" towards Arin is platonic (he has always treated her as a part of their family ever since) or romantic like his other brothers. Id prefer if it was platonic tho cuz we dont need even more pseudo incest in this story T^T and I think it'd be quite interesting if he also had some loose screws in his head to not even care that his little sister wants to shake up the whole family since he knows how they have been treating her this whole time.