Delta Stream ability

Creates a mysterious air current, which cannot be replaced and causes moves to never be super effective against Flying Pokémon.

Effect: When this Pokémon enters battle or gains this ability, the weather becomes a mysterious air current. A mysterious air current causes moves to not be super effective against Flying; they do neutral damage instead. anticipation and stealth-rock are not affected. The mysterious air current ends when this Pokémon leaves battle or loses this ability, or when this ability is nullified. The weather cannot otherwise be changed except by the effects of desolate-land and primordial-sea. air-lock and cloud-nine will prevent the effect of a mysterious air current, but will not allow the weather to be changed.

All Delta Stream ability Pokémon

Pokemon National#		Type	Abilities	Stats
				HP	Att	Def	S.Att	S.Def	Spd
	Mega Rayquaza (Rayquaza) #384	Dragon Flying	Delta Stream	105	180	100	180	100	115