SketchUp
Don't let your memes be dreams
To tag a person type @ and the name of the user you want to tag right afterwards.thx you so much SketchUp (damn idk how to quote your name, tag or whatever)
But I can't see the utility of Skill Swap (just for m-sable i guess ?_?)
Skill Swap can steal many useful abilities outside of Magic Bounce. Pokemon in OU you really bother if you swap their ability: Azumarill, Breloom, Clefable, Conkeldurr, Gardevoir, Gliscor, Gothitelle, Landorus-I, Sableye, Slowbro, Sylveon, Altaria, Diancie and Thundurus.
Gothitelle and Mega Sableye are the most important, because you can escape from gothitelle and you can status mega sableye.
Azumarill, Mega Gardevoir, Breloom, Sylveon and Mega Altaria all miss damage and they can't hurt Cresselia
232 SpA Mega Gardevoir Hyper Voice vs. 252 HP / 0 SpD Cresselia: 93-110 (20.9 - 24.7%) -- possible 6HKO after Leftovers recovery
252+ Atk Choice Band Azumarill Knock Off (97.5 BP) vs. 252 HP / 252+ Def Cresselia: 124-146 (27.9 - 32.8%) -- 79.1% chance to 4HKO after Leftovers recovery
+6 252+ Atk Mega Altaria Return vs. 252 HP / 252+ Def Cresselia: 275-324 (61.9 - 72.9%) -- guaranteed 2HKO after Leftovers recovery
252+ Atk Choice Band Azumarill Knock Off (97.5 BP) vs. 252 HP / 252+ Def Cresselia: 124-146 (27.9 - 32.8%) -- 79.1% chance to 4HKO after Leftovers recovery
+6 252+ Atk Mega Altaria Return vs. 252 HP / 252+ Def Cresselia: 275-324 (61.9 - 72.9%) -- guaranteed 2HKO after Leftovers recovery
Other: Gliscor loses recovery, Thundurus gives you prankster and slowbro gives you regenerator. You can status Mega Diancie, Clefable and Mega Sableye with no drawbacks