James- Pride

Listen, no matter how much he'll deny it. He has an ego, it's just not boastful, and is it really an ego if he can back it up? He carrries a silent superiority to him. Jamie thinks VERY highly of himself and is ass at listening to others, so he places himself as the leader in literally everything he does. Like I've said before, he's a control freak and perfectionist and hates not being in the know. I think of him as lawful good, but like in a way where he follows his own rules and bends others (he never breaks them though, always with the plausible deniability this guy). To put it simply, yes, he does assume he's the smartest in the room and constantly acts like he's got smth to prove (he's got severe imposter syndrome gang+ superiority complex+inferiority complex someone help him)

Albus- Envy

Albus is full of anger issues, middle child angst and envy. He constantly compares himself to everyone around him and unlike James, his fear of failure doesn't motivate him, it keeps him stagnant. Albus just kinda sucks at magic, it's not one's fault, logically, he knows this, but everytime he hears "when James was your age" or " your brother got this spell on his first time" it leaves him seething. Rose is the top in their year, his best friend barely behind her and Al is failing most of his classes. Its not his fault, its James really, he set the bar too high. Its not his fault (another inferiority complex here they must've been on sale)

LilyLu- Pride

Overconfident is the only word to describe her. She thinks she's the shit, and acts like it, girl could get her ass beat several times and leave that fight thinking "Yeah, it was pretty close ". Some of it is just a bit, but like a decent amount is genuine, shes a braggart. Lily is incredibly stubborn and tends to do her own thing with poorly thought out plans and a prayer. Her and James usually clash over this, he just sees her as an immature child and she sees him as a child cosplaying an adult. She feels like she can't do anything in his presence without him showing up like "erm you're doing it wrong". She acts without thinking very often. I think she believes in the Harry Potter myth more than any of them. She takes pride in being a Potter.

Bonus-