I was fighting in a tournament when Marshadow-GX, with 5 Psychic Energy attacked my Celesteela-GX with Moon Press eventhough my opponent doesn't have any Celesteela-GX on his discard pile and I don't even have a Celesteela-GX on my discard pile.
This Pokémon can use the attacks of any Basic Pokémon in your discard pile. (You still need the necessary Energy to use each attack.) [Source: bulbapedia.bulbagarden[.]net/wiki/Marshadow-GX_(Burning_Shadows_80)]
Is this a bug or something? I lost a tournament because of that Marshadow Moon Pressing me.