All right all right, @champagne_supernovas, let's go! Top down on Dominick…
On this nature page, I'm seeing a lot that doesn't make sense. An honest and caring person who tends towards cruel manipulation and mind games doesn't make sense. Distrustful and faithful are basically opposites. A laid-back person who's also ambitious? A deep and passionate person motivated by sheer spite? There are a lot of contradictions here. But I don't think it's completely blatant contradictions here. I just feel like nothing's fully explained. You have laundry lists of traits here–that's cool, because you write these in a way that you understand–but that makes it hard for us critiquers to delve into your character's mind. I feel like you need to explain how these polar traits Dominick has manage to coexist. That being said, I will go into the contradictions I saw a bit more.
First up is honest-versus-manipulative. Honestly, most of his flaws seem out of place like this one. Because a caring and honest person wouldn't be destructive and manipulative and cruel at the same time. I think what you need to do here is establish some lines. Is Dominick a polar character, kind to his friends but aggressive towards others? Or is he a guarded character, who's kind deep down but lashes out for some reason? Or does he manipulate out of perceived necessity, and he's grown disturbingly good at it?
Then comes the conflict between distrustful and faithful. Again, you need a line–what does someone have to do to gain his trust? And more importantly, what in his past made him distrustful?
Laid-back and ambitious. Is laid-back a front to look cool? Is his ambition to please his parents or some higher-up, and is draining him because it's not what he wants? Really, these are all just explanation complaints. The other option is to rework his traits and scrap some of the conflicting ones, which also works well (or at least it has for me)!
But his motivation of spite isn't something you can explain away so easily. For someone deep, caring, and passionate, it doesn't make sense that Dominick's main motivation in life would be proving others wrong. I could understand how that could be a superficial motivation, born out of his past experiences, perhaps with invalidation. But for him, I would expect something more like stability or love or success. Even fun. Spite seems wrong somehow–as a main motivation. As a petty or secondary motive, I think it works just fine.
Also, real quick, where are his prejudices? Every character has them, whether they realize it or not.
Backstory is solid, but I do have a couple points and questions. First one is a simple clarification: you say that his father died when he was six, then say that he accidentally killed him during his sophomore year. Not sure which one of those is wrong, but one of them must be.
Question: if his parents had been on heroin for so long, how was he born safe and healthy? I doubt his mother would've been able to quit while she was pregnant if she was fully dependent. Another question: How is Dominick… okay? If he grew up in a household with drug-addicted parents and an uncaring father, just to accidentally kill that father and then witness his girlfriend die right after becoming a young father, how in the world has he managed to stay stable? The way he becomes a bad boy is painted as a depressive spiral, but that doesn't play out in his personality. I think it could be cool to explore the impacts of those events a little more!!
Also, before I wrap up, is his mother… okay???? Did she actually have/adopt 15-16 kids?? If her husband died when Dominick was a sophomore, she wouldn't have had the time to do that–biologically speaking.
But hey, that's all!!! I'm sorry if I got a little blunt–I feel like I might have. But I promise I'm trying to be constructive!! You have a well-written character here, I'm sure, but some of his traits just require further explanation. I hope that what I've written helps you with that!! :DD