Way I see it, Urbel blames mostly the murderbot (as he is want to call it) and himself for the mess. He is completely unaware that Brad was partially responsible for the dam collapsing on itself, so as far as that is concerned, he has no reason to hate him in particular. In fact, given that he uncovered that scientist death (rest in piece, unknown plotline, you shall be missed!), he actually likes him a lot more than the other droids. Still thinks he has far to much spending in him, though, and frankly Urbel's a hotblooded asshole, so greetings might be rough at the get-go.
After that, though? If he is willing to team up with Urbel on his quest, or has a lead on magical know-how? Urbel game for that. Hell, once he gets to know your character a bit, they'll be have a devoted ally on their side. Social reject status makes him very keen on the few friends, you know?
If we are going to have another quest together, I already have a plan in mind. Right now, Urbel's heading to Mimiga village to find resources to restock. Having Brad meet up with him there would probably be for the best. Especially since I have a plotline that involves teleporter senanigains and confused dragons. Fun fun fun!