Quoted By:
Last week before ORAS release, GameFreaks announcement :
"We have realized that mega-evolution actually reduce the diversity of the game in regard to pokemon abilities. So effective from ORAS launch and XY patch, mega-evolving now add a second ability to the pokemon your are mega-evolving instead of replacing it, effectively more than doubling the number of available mega-strategies and rendering mega-pokemon more epic than ever."
Which is your mega of choice with this change guys ? Which are screwed / redeemed ?