On 3DS
In yesterday’s update to Pokémon Shuffle on the 3DS, new main stages were added, finishing out the Albens Town area with Mega Medicham as its boss. You don’t care about Mega Medicham though (especially since we already have Mega Lucario as a go-to Mega evolving Fighting-type). No, you care about Gardevoir.
This should come as little surprise to those who have been following along. The first Albens Town update added Ralts at Main Stage 217, then the second added Kirlia at Main Stage 223. Gardevoir rounds out the evolutionary line at Main Stage 238, just two levels before the boss.
Currently, Gardevoir is only available for Pokémon Shuffle players on the 3DS. Pokémon Shuffle Mobile is still holding back its main stage repertoire in order to stagger release. It currently goes as far as Main Stage 180 (Mega Aerodactyl).