>>22090117Mega Gardevoir rose to prominence along with Mega Medicham and Mega Heracross after Aegislash was banned. Spookysword walled all three, and forced them to run sub-optimal coverage moves just to 2HKO it.
In the post-Aegis metagame, they became known as the big three wallbreaker Megas. They completely manhandled stall, and all rose to top OU.
Gardevoir is amazing because Pixilate Hyper Voice 2HKOs almost everything, Psyshock 3HKOs Chansey, and it runs Taunt to disrupt and block healing moves and such.
In the ORAS meta, Sableye Stall is a team archetype (like offense, bulky offense, ect.). Mega Sableye is a metagame-defining force that is insanely good for stall. Mega Slowbro is also quite good, I've heard. Mega Gardevoir completely destroys both of them.
It's really fast for such a powerful, bulky Mega too. Definitely an A+ rank threat.