I've been considering going for a Warforged who has grown to regret his original purpose and is quite hesitant to do any acts of violence. While he still could, by design.

An alternative idea is a Tiefling who is just totally fed up with the general view of his kind and, while holding a lot of internal anger he might release towards those too provocative, tries to prove that not all of his kind are what they say. A bit of a comedy aspect about him could be that he's also sort of a bodybuilding individual, so... huge.

Please tell me if any of those two ideas actually make any sense :)