I made a Mega Gardevoir EX deck around Steam Siege's version of this Pokémon. I considered ways of playing it, and different cards to insert into the very flexible deck it seems to be.
For now, I prefer to play it inside of a fast build with a two shot based strategy with healing. After a few changes, my Despair Ray deck looks as follows:
Pokémon - 12
2 Hoopa EX AOR
4 Gardevoir EX PCL
3 M Gardevoir EX STS
3 Shaymin EX ROS
Trainer - 39
3 Fairy Garden
1 Brock's Grit
2 Hex Maniac
2 Lysandre
2 N
4 Professor Sycamore
2 Skyla
4 Fairy Drop
4 Gardevoir Spirit Link
3 Mega Turbo
4 Trainer's Mail
4 Ultra Ball
4 VS Seeker
Energy - 9
9 Fairy Energy
Let me know if you think I should add/cut certain cards and how you build or would build it.
Any suggestion will be considerated.
Anyway, the goal of my deck is to deal two shot Knock Outs to my opponent's Pokémon by dealing 110+ damage every turn, most of the time starting on turn two, and make it extremely hard for the vast majority of my opponent's Pokémon to take prizes, thanks to Despair Ray's capabilities to discard any stalling targets and easy prizes. In addition, healing cards, the Fairy Drops that is, make Mega Gardevoir potentially hard to Knock Out in two hits. Fairy Garden allows to easily retreat between Mega Gardevoir once the Active one is highly damaged and Despair Ray even allows for more prize denial in that it can, as a last resort, discard heavily damaged Mega Gardevoir on the Bench. Due to the two Energy cost and the presence of Mega Turbo, it is extremely easy to power this attacker up and any Energy scaler (especially Mega Mewtwo) will be given a hard time (same thing for Bench scalers since my Bench can be cleared easily). Speaking of which, Mega Gardevoir benefits from two types, which lets it hit most Psychic types Pokémon (Mewtwo, Alakazam, Hoopa) for Weakness as well as one shot every Dragon type Pokémon, such as Latios, Giratina (with Hex Maniac), Salamence and Rayquaza. The presence of two Hex Maniac allows for Ability Disruption, sometimes even on turn one, and potentially on many turns, which is very painful to decks like Volcanion EX and Greninja BREAK.
What is your favorite way of playing Mega Gardevoir EX, the Steam Siege version? Do you think it is a good deck at the moment? What techs do you like using? Let me know, I honestly think this deck is better than what it is often seen as being. I would like to know if it is good against most of the meta.