Well if you can get rid of Tyranitar, Rotom W, Scizor, Ferrothorn, Specs Politoed, Heatran, Jirachi, Skarmory, Excadrill, Thundurus, Reuniclus, Gengar, Taunt Gyarados, Deoxys, Volcarona, Forretress, Latias, Hydreigon, Scrafty, Metagross, Chandelure, Toxic, Sandstorm, Hail, Rain, Sun boosted Fire Blasts, Taunt, any offensive Pokemon with Lum Berry, stall and all skilled players then Cresselia is decent in OU.