Gothita probably does it better, Shadow Tag is broken as hell.
Gothita doesn't get Stored Power. Ralts also has better defensive stats.
Gothita probably does it better, Shadow Tag is broken as hell.
Gothita also doesn't get Shadow Tag yet.
252+ Atk Huge Power Marill Superpower vs. 4 HP / 0 Def Lotad: 242-285 (63.35 - 74.6%) -- guaranteed 2HKO
-1 252+ Atk Huge Power Conkeldurr Superpower vs. 4 HP / 0 Def (custom): 162-191 (42.4 - 50%) -- 0.39% chance to 2HKO
252+ Atk Huge Power Marill Ice Punch vs. 4 HP / 0 Def Lotad: 152-179 (39.79 - 46.85%) -- guaranteed 3HKO
252+ Atk Huge Power Marill Superpower vs. 252 HP / 0 Def Lotad: 242-285 (54.5 - 64.18%) -- guaranteed 2HKO
-1 252+ Atk Huge Power Conkeldurr Superpower vs. 252 HP / 0 Def Lotad: 162-191 (36.48 - 43.01%) -- guaranteed 3HKO
252+ Atk Huge Power Marill Superpower vs. 252 HP / 252+ Def Lotad: 181-214 (40.76 - 48.19%) -- guaranteed 3HKO
-1 252+ Atk Huge Power Conkeldurr Superpower vs. 252 HP / 252+ Def (custom): 121-143 (27.25 - 32.2%) -- guaranteed 4HKO
252+ SpA Life Orb Lotad Giga Drain vs. 4 HP / 0 SpD Marill: 281-330 (87.26 - 102.48%) -- 18.75% chance to OHKO
4 SpA Lotad Giga Drain vs. 4 HP / 0 SpD Marill: 156-186 (48.44 - 57.76%) -- 47.27% chance to 2HKO
Marill is Huge Power, Meditite is Pure Power. And Meditite isn't really a problem, its actually relatively slow and doesn't have very great defenses. It also doesn't get STAB on its priority move, and said priority move is a bad attacking type.
But let's say it is OP; why ban both those abilities? Azumarill and Azurill aren't necessarily OP and Medicham would almost definitely not be.