Really the fact that he’s ~actually a dragon~. Related to that: when he joined the Argent crusade, while he said he was a paladin, he had no idea how to use the Light at all, and kinda cheated w/ his own magic. After a while, the talk about believing in the Light finally sank in, and he was able to wield it. He’s actually pretty decent at it, because as it turns out it’s a lot like his own magic anyway.