When you play Gengar from your hand to evolve your Active Pokémon, you may put a Basic Pokémon (excluding Baby Pokémon) from your discard pile onto your bench. Then flip 3 coins. For each heads, choose a basic Energy card from your discard pile and attach it to that Pokémon.

Flip a coin. If heads, the Defending Pokémon is now Burned. If tails, the Defending Pokémon is now Confused.