"Hm, speaking from an objective point of view, I see two strong possibilities. The first is that you are correct, that this man has a good heart, and your oath's reaction is based purely upon his species or craft, as opposed to his actions. The second..." Sarael hesitated. "And, I apologise if this comes across as cruel. But the second likely possibility is that ... it is as you say. You want to believe that he is a good person, but you know at heart that he is not. You know that, and you knew that, and that is why your sword has turned against you. I do not believe such an oath would make allowances for denial."
"Owch..." Ari muttered. "Harsh. I mean, nobody's inherently evil, right?"
"... arguably, certain denizens of the lower planes or other entities with moralities hardcoded into their essence might-"
"Okay, nobody relevant to this discussion," Ari cut in, heading off Sarael's extrapolation.
"Ah. Philosophically speaking, no. Even a man who has performed evil acts, and harbors intent and desire to perform more, may not themselves be evil. If this man is not a good person now, it is likely that he has the potential to be. The relevance that this has to your oath, however ... I do not know." Sarael smiled apologetically. "It may be that Sylvire's wisdom can help you more."