Diantha arrived to the café and stopped Lysandre from intimidating the children. Diantha was displeased about Lysandre, who intimidated the children, hardly considering that an act of beauty and Mega Evolved her Gardevoir to protect the children.
Diantha had Gardevoir use Psychic to stop Skrelp from attacking and lifting Gurkinn out of the water. Diantha then faced Chalmers and had Mega Evolved her Gardevoir, who used Psyshock to counter Dragalge's Sludge Bomb. Due to its new ability, Pixilate, Mega Gardevoir fired Hyper Beam, which turned into a fairy-type move, which defeated Dragalge. Facing a thief, Diantha sent Gardevoir to battle the thief's Binacle, along with Gurkinn's Heracross and Korrina's Lucario. Since they were facing Binacle, who used two of their heads at once, Diantha Mega Evolved her Gardevoir.
Dinatha, along with Korrina and Gurkinn, arrived to protect the Xerneas tree. Diantha Mega Evolved Gardevoir, who started attacking. Malva appeared and challenged Diantha, having her Braixen trap Diantha and Mega Gardevoir inside the Magic Room Malva was surprised Magic Room did not negate the effects of the Mega Stone. Nevertheless, Braixen used Fire Spin, which Mega Gardevoir dodged. Malva expressed her real intention is to trap Diantha inside, as Diantha, Malva and her Pokémon were trapped into a sphere, which sank into the ground itself.
Seeing Y's progress during his training, Gurkinn had thought of Korrina, Diantha and her Gardevoir, wondering if they would approve if he gave Y the Key Stone.
|Psychic (move)||X & Y arc|
|Psyshock||X & Y arc|
|Charge Beam||X & Y arc|
|+ indicates this Pokémon used this move recently.*|
- indicates this Pokémon normally can't use this move.