There are a lot of abilities that could suit this pokemon well. The water aspect opens alot of defensive abilities such as hydration, water veil, water absorb, rain dish, swift swim, and even marvel scale. Fighting opens iron fist, huge power, no guard, technician, Intimidate, and Vital Spirit. As we found out, it is leaned defensive slightly. Huge Power might be an interesting go here supplying a possible OU Azumarill. No guard as well as Swift Swim provide some usful power bonus', since a majority of the pokemon are defensive. I'd like to see Hydration and Marvel Scale (if we can justify it) used, providing some strong defensive capabilities.