I already have 4 Pokémon capable of Mega Evolution: a Lucario, a Blastoise, a Blaziken and an Ampharos.
However, when I activate Mega Evolution for one of them, then switch out my Pokémon, the button for Mega Evolution is greyed out (inactive).
I understand that for balancing purposes, you shouldn't be able to fight with multiple Mega Evolved Pokémon simultaneously, but is there a way to reset Mega Evolution in order to Mega Evolve another Pokémon while still in combat?
Best Answer
No. You can only Mega Evolve one pokemon per battle.
http://www.serebii.net/xy/megaevolutions.shtml