@Terminal, I'm still not quite sure if I quite grasp the first part of the prompt, particularly the "ambivalent" part. I understand the two extremes (basically outcast and the moral compass), but would the following be an accurate picture of what the main character should be?
<Snipped quote by Example>
I only meant that they cannot be either wholly 'good' or 'bad.' An ambivalent person has virtues and failings which conflict with one another, but the end result is not so much a person who gets in their own way so much as a person posessing Grey morality. This character's traits and such, while they can impede them and hold them back, are not required to for the purposes of the challenge.
If they get in the way of their wishes and goals, fine. If not, that's also fine. Either way, without change, they must fail. For the former it may or may not be because of the conflicting facets of their being. For the latter, other forces may be at work.