Yeah, so Brauk isn't really a 'villain', but he also isn't exactly everyone's most favorite character. Especially after he mistreated Echofrost, and even ripped out her flight feathers. I honestly think that Brauk more of a brat then the books let on.
I get that it must have been hard on Brauk when his mother died, but come on. He abandon his only brother, and gambled almost all their money away. Then he used his the rest of it money to buy Kol. Yeah sure, Rahkki loved his brother's flyer, but seriously dude? You hogged all of your families money for yourself!
Because Brauk had used up all his money, both he and his brother had to live in poverty. Rahkki had to work day in, and day out to make sure Kol was well taken care of, wile Brauk flew over the jungle. And when Brauk couldn't afford to take care of his brother, and Kol, it was Rahkki who got sent away. It was Rahkki who was forced to work on Uncle Darthan's farm.
If you think about it, Brauk was treating Rahkki like a slave for most of the book. I don't know if Brauk really cares for his brother, but she sure doesn't act like it.