[@NuttsnBolts] Gotcha. Really need to marathon avatar, it's been so long since I've seen one of the original series episodes. I'm thinking either a Dai Li inquisitor corrupted by the splinter group, or maybe a water-bending assassin with special interest in earth-kingdom contracts, due to the tensions you described in the OP.

Also, in reference to number 5: Maybe the airbenders host a competition or festival to try and help defuse things and soothe some of the tensions?