How is Goldenloin described in the novel, Nimona?

Goldenloin is described as very proud, and he hates to lose at anything. As a result, he will do immoral things to get his way. He is former best friends with Ballister, having studied with him to be heroes at the Institute. After losing a joust to Ballister, Goldenloin mercilessly shot off Ballister’s arm. Goldenloin claims it was an accident, and is believed by all but Ballister. Goldenloin is ultimately assigned to kill Nimona, though he has qualms about a hero assassinating anyone. Nevertheless, he agrees to do it to preserve his job.