Mew

Poke-POWER — Type Change: Once during your turn (before your attack), you may choose 1 of the Defending Pokémon. Mew is the same type as that Pokémon (all if that Pokémon is more than 1 type) until the end of your turn. This power can't be used if Mew is affected by a Special Condition.

Link Blast (50): If Mew and the Defending Pokémon have a different amount of Energy attached to them, this attack's base damage is 20 instead of 50.