[@Timemaster] of those three, I think the first would work the best. It's more versatile, it seems balanced and you seem to have a good backstory in mind. The second would just be boring, given the story established so far; either they succeed with their power and the beast is neutralized, or they don't and they're useless. For the third, the first one seems interesting but I'm not sure how it'd play out RP-wise. The second would probably work better in a D&D sort of combat system than in a writing-based play by post sort of thing going on here.

I'm not trying to be overly negative, so my apologies if the second or third ideas were the ones you preferred. Just trying to provide an interesting writing environment!