Isn't that the usual?
Well he really didn't change tho, he was just forced to. The police just made up some assumptions that he and his sister are brainwashed even tho they are not.
he has the right to be a cocky jerkass, both him and the girl were taught by an archmage, I repeat, an ARCHMAGE, if Shirone wasn't there, then the school would've been doomed from the start, he's strong af and he knows it, also let's not forget how the police robbed them of their inheritance from their master all because of that stupid jackass police #－.－)
I feel so conflicted about Canis (Is that his name?). On the one hand, people should be given another chance. On the other hand, Canis doesn't seem to have changed or reflected on his action much. He still seems to be a cocky jerkass as always.