A fairy deck that focuses heavily on healing.
Max potion + Aromatisse is a full healer
Fairy drop + Sylveon EX for big heals.
Main attacker is Sylveon and Gardevoir GX. When both fairy garden and Aromatisse are in play, simply retreat this with a benched Sylveon and Gardevoir for viturally a full heal. Then heal off any damage from the first one with whatever method is available.
The objective is to continuously attack the opponents hand with Marnie's and eventually the Sylveon and Gardevoir GX attack when the energies are available. Wondrous Labyrinth and crushing hammers are there to slow your oppenent down. If you need more than a 150 attack, Xerneas (LT) or Xerneas BREAK are there to hit hard.
Energy accelerate with Sylveon and Gardevoir GX and Xerneas (SS).