I don’t know. Witchers aren’t really fueled by their alienation, and it’s more an emergent property of the racism and xenophobia of the setting than something built into being a Witcher. The games hammer home Geralt’s position as an outsider; the books do not, and in fact he seems considered entirely a (mutant) human.
Feeling like an outsider, defending humanity from monsters but not truly a part of humanity, is great Belief fodder. I’m not so sure it’s an ideal emotional attribute.