I like Sorrell's and Livi's backgrounds. What I've been thinking for Lou is complicated as per usual. There is no actual time line, but I hope you'll get the gist.
Louis is the first born in the Maddox family. He has two younger brothers, two years between each of them, Lucas and Landon. Their father is named Michael and mother is Annabeth. However, they are a broken, complex family. Just like any other family, really, because each is sad in their own way. Annabeth left their father when Louis was thirteen, because she fell in love with another woman. This really hurt Michael, and he turned to the bottle to drown his sorrows while trying to raise a flock of now motherless boys, who refuse to see their mother because they all feel betrayed. They don't have any pictures of Annabeth in the house, and it's been six years now, and Lou admits that he's started to forget what his mother looks like. She tried in the beginning to keep in contact, but Louis was the one who told her to keep a respectable distance because he was afraid it would be bad for Michael. Lucas and Landon refuse to understand because they were so young when Annabeth packed her bags and left, and all they see is their miserable father who looks like he wants to fold in on himself whenever someone brings up their mother. His younger brothers are angry at their mother for it, and Lou thinks it's just better if she never comes back at all. It has been his call as the oldest brother. This really broke Annabeth's heart, but she respects the wishes of her son, and keeps to her girlfriend.
Overall they are not much. Just a regular working class family, trying to get by. The only way Louis and his father knows that Annabeth is still out there is that she pays her sons educations, because Michael could never afford them. Because of his drinking problem, Michael was out of job for couple of years, but lately he has gotten back around to it. He still has his regular bottle for every Friday, but the boys do not say anything about it. It's Michael own battle, and he is trying. And that is what matters. All of them inherited the magic from Michael's side, so the whole family is Physical Casters. (But only Louis is the one born without a familiar, and nobody knows why that is, not even the doctors.) Louis is the most prominent of all the brothers, because he is the one who taught his younger brothers usually instead their father, because Michael was usually either drunk or sleeping it off. Michael may be considered officially the head of the family, but it has been Lou who has been looking after it. He does it out of worry and love, and not to get recognized, so Lou does is subtly and mostly in silence. This is how he has become a reliable young man and how he so easily finds himself on top of things. It's just natural for him.
Lately things have gotten a bit better, and as said before, Michael has gotten a job; just some grunt work at the local factory, but it's a start. Louis still sometimes gets frustrated with his father, so it is not that unusual for them to butt heads, because they're both pretty strong personalities. They always keep their fights verbal, and never has Michael raised his hand against any of his sons, no matter how drunk he has been, which Lou is glad about. Michael may be a broken man, but he is a good broken man. In the end they always apologize to each other, in their own quirky ways because like father like son, they are really bad at saying sorry to each others faces, so they do favors to each other in silence; help prepare dinner, do little tasks for the other, buy little gifts. Lucas and Landon think both Michael and Louis are stupid, immature and embarrassing, and that they should just make things easier and get over themselves and say sorry, because every time this goes down it is really ridiculous to follow from the sidelines. Their home is loud and lively, and a bit messy, and the food sucks, but it's a warm home. Sometimes when Lou feels like he needs silence, he packs his bags and goes to hike in the nature during holidays. During summer vacation, he might be away from home for weeks at a time.
Not having a mother figure in the family, living with three other males and going to all boys school is why Louis has become pretty crass and masculine personality wise. Femininity is rather nonexistent in Lou's life, which is why he regards it as something alien and a bit weird. Also why he is so eager to label all the girls as he does, and so ready to step on this school rivalry without question. It is not really hard to get Lou riled up for it at all.
However, for a young man, Lou is a bit lost. He has been so busy with keeping his family together and looking after his father and brothers, that he has not really had the time to think about what he wants from his own life. He's nearly graduated and Lou has no idea what he wants to do when he "grows up" and whatnot. All he is good at is casting, but it is also breaking him apart because he has no familiar. It is not like he can make a career out of it because it is killing him. And Lucas and Landon won't be needing their big brother forever, they will grow up and leave the nest eventually, too. And there is no way Louis will stay home to look after Michael, he's a grown man and needs to stop relying on his first born to do it.
So that's what Lou is all about. Any thoughts?