He's not perfect but by gods is he far from what I'd consider toxic when it comes to MLs seen here
What toxic he does dote on his sister but doesn't neglect mc, is somewhat respectful not from the beginning, no cheating or misunderstanding abt it, just a typical black haired red eyes ML
RIGHT like bro there is "bad" before "toxic" but he's not even that, he just is!! He's not perfect but for the level of depth this story has, he is very good with all the points you mentioned. Also, his doting on his sister is not the weird kind often seen in rofan but more normal (still somewhat over the top but for the standard? Not at all). He treats MC with respect and his suspicions of her in the beginning were completely justified imo - and the fact that he genuinely cares for her as a person, not as a fiance or white mage, p quickly as well (yes the bar is in hell ), and how quickly he made sure she joined in on the family (ie. the first family dinner).
bro I know that I'm not supposed to like the ml cause he really ant all that but seeing his smile I forgot why I was mad at him I dead ass need help dude cause I'm starting to like toxic mls more and more man