He's being a dick to his own child instead of giving it to her like she wants.
Well, to be fair, being a young adult one day and on the other some weird supernatural thing does some weird shit which results in a girl that almost appears older than the kid claiming to be his daughter is not the tipical father-daughter relationship and i do believe its the right thing choosing not to even try to depict as such. There is nothing that could be considered normal about it. He wasn't prepared for it, wasn't asked about. Here have yourself a daughter who is kinda emotionally unbalanced, is supernatural, clingy and needy... i don't see how the kid should be more 'considerate' considering he was never asked for consent for anything. You expect him to be a proper dad? How? Everything wad decided for him, instead of him. If we have a victim here its the mc. His mom? Total failure as a mother, the tears and monologues of how much she care? Absolute bullshit. Dad? Pffff. Superfairygrandmistress? She is not the "what would you like" type, dropped a supposed daughter on top of the kid's head.
All she wants is love, being loved? The boy didn't asked for it. Its nice that she wants it but.. when did any of these entities asked the mc what he wants BEFORE deciding themselves, instead of him, what will be good for him and pretty much just expect him to deal with it and put on a happy face. I wouldn't be happy at all.
Those who really care about him are not from this group. Its from the Veronica group. I do understand D's issues.. the problem is that the boy has some very legit issues too and nobody seems to care about those, everyone seems to be expecting him to be considerate (to put it simply) for their own selfish reasons. This isn't about the mc and it seems to me that he absolutely has to be a dick to make it clear for everyone, D included, that its either going to be mutual or none at all. He tries. Imagine your girlfriend killing your parents, best friends because she wants more attention from you because one day you didn't wanna go on a movie with her and she took that somewhat personal. The kid realizes that D can't be handled like just a normal being and lets be honest.. how the hell he suppose to know how to handle a supernatural demon-like being who is kinda clingy. I haven't got a textbook on how to tackle emotional turmoils of demonic beings. I bet he didn't either. He just goes with the flow and personally i do like the fact that he isn't doing it the best possible way he may could have been doing it. Makes him appear more believable. Someone with real issues. Someone who wasn't up for this shit but he has to deal with it anyway. He is rude because he is scared. He doesn't know what to do. He doesn't know how to handle D and he pours it on her because frustration doesn't have an off and on switch and D doesn't ever ask if he needs company or anything, she forces herself upon him. And he is just a kid who became a father overnight which he never asked for but wasn't asked about it and he has to deal with it. Maybe in a year or two? We aren't there.