Imo the paladin oath of vengeance would be more like the RedHood than Batman ^^, or perhaps Judge Dread.
What's fun with this kind of characters is how they will handle their very first levels. If they charge everything and won they'll not stay alive when the first big bad will come. If they're kicked bad, they'll grow more subtil and will be more fun to play. It's why session 0 and the beginning of a character career are important, they'll define everything else about him.

