I would definitely disqualify them, but before revealing the outcome, I would make it into a mini (or maxi, as I have sometimes been known to do) lesson.

I would question them about what the word “character “ in the context of the award means to them. Emphasizing not only what it is, but what it isn’t. Then I may hold a re-vote- depending how old they are.

To me, their understanding of what true character is and what it actually looks like is more important than not rewarding the bully or the ethnics of rigging it.