Yveltal-GX

Absorb Vitality

Heal from this Pokémon the same amount of damage you did to your opponent's Active Pokémon.

Sonic Evil

This attack's damage isn't affected by Weakness or Resistance.

Doom Count-GX

If your opponent's Active Pokémon has exactly 4 damage counters on it, that Pokémon is Knocked Out. (You can't use more than 1 GX attack in a game.)