My counter for belly drum azumarill,
def type: Venusaur (sludge bomb, giga drain), tentacruel(sludge bomb, haze), and weezing(sludge bomb, thunder bolt, haze)
You should have at least one of those coz if you notice many are using azumarill nowadays. You can't stick with your beloved team forever. Every week a new pokemon was being introduced in pvp ladder. If you having trouble don't stop there. do some countermeasures. :y: