Just like in everyday life, the people we meet in books should have a diverse assortment of personalities. We as authors want our characters to be likable, or at least memorable. I build up a personality profile for each of the characters, and do my best to hold them to that. There have been a few scenes that when I wrote them, I needed a certain outcome to happen that my characters just wouldn't perform. A few times I brought in another character that would give me the result I needed. Oft times this leaves me contemplating just how large of a role to give to these impromptu characters. Traxell was one such impromptu appearance, and his personality changed a few times during the writing.