Brax is an NPC I had hovering in the background of the Angry Priest Inn. I don't think anyone had an encounter with him. He's a not so reliable henchmen for hire. He's not a bad fighter, sturdy and willing, for the most part. His loyalty is to acquiring things, not people. If paid well he'll stick around, but even still, if offered the chance to scoop his hand into the party's treasure chest he would not hesitate. Brax is a master at justifying his shitty behavior.
The entire picture of Brax didn't come together until I found this piece from Luigi Castellani. That's when the cool details that his armor is made of old tankard bottoms, his anti-spider ties and his gorgeous mustache. Meet Brax of the Blue Pants.
As far as GM advice with Brax...because he's been banished by the dwarves, any dwarf in the party would see his sheared beard and know he is a criminal. Brax himself is likely to stay away from parties with dwarves. He believes they are untrustworthy race who betrays their own. Nevermind all the stuff he did.
If Brax is hired on, he doesn't complain and in general, do what he's told. But if left alone with valuables around, he'll take what he thinks he can get away with.
As far as spiders go, he's out. Even little ones terrify him. Screams like a little girl and runs. Even if someone talks about spiders he gets paranoid and he'll swat at his legs thinking spiders are crawling on him.
I hope you guys can find a place for Brax somewhere in your game. I think he's a fun NPC to have around.