maybe azumarill(holds lum berry) use belly drum can deal with blissey + slowbro
if bro use thunder wave then azumarill has lum berry. i don't know what pkms can take play rough(next turn) by belly drumed azumarill and not die.
if bro use surfing or flame thrower then azumarill will still be alive. next turn bro will take play rough and die.
the only way ur opponent can do is switch bro out while azumarill using belly drum and switch in scizor , talon flame, dragonite and some priority pkms or some tanky
grass, steel, water type pkms that can outspeed azumarill and would not get ohko by azumarill's aqua jet.