You know,If Greninja does Get banned,Mega Slowbro might become all that more dangerous.Greninja is a decent check to Slowbro in that as long as MegaBro hasnt set up yet it gets 2HKO'd by the Dark Pulse with a 31% Change for the OHKO.
252 SpA Life Orb Greninja Dark Pulse vs. 248 HP / 0 SpD Slowbro: 351-413 (89.3 - 105%) -- 31.3% chance to OHKO
(351, 354, 359, 361, 367, 369, 374, 377, 382, 385, 390, 393, 398, 400, 406, 413)
Keep in mind that said Damage Calc does not have Mega Slowbro in there yet so i put in Mega Bros Stats.
Taunt does shut it down completely so that's a blabant counter.Sableye is a blabant counter in both forms,though only if it runs taunt as otherwise,Slowbro can and probably will set up calm minds.