Pyoro posted:
Urgh, I hate that sort of "rescue somebody" romantic/friendship development. Guy's been an asshole to her the entire time, but, hey, it's okay, but he's shown some basic decency once ...
I think that his own circumstances make that he does not open easily to others. We can infer that he's an illegitimate child from some high ranked angel, that's been abandoned to his own device and found refuge with Sera who actually sees value in him.
He seems to be very serious about his job. From the reaction of the other demon, we can see it's not the first time he snaps. And we can also see he's quite ripped (arms and abs) so he's not to be trifled with.
To be an asshole is his own defense mechanism against being used. I think that after spending some time with Ganko, he realized that he's been unfair to her, because she's not like other people : she's really innocent and she doesn't judge him. Plus, the fact that he seems to hate the idea of rape that could lead to a child.
So, I don't think it comes out of nowhere. It's character development.