Dusknoir

It is said to take lost spirits into its pliant body and guide them home.

Ability — Shadow Void: As often as you like during your turn (before your attack), you may move 1 damage counter from 1 of your Pokémon to this Pokémon.

Pain Pellets: Put damage counters on 1 of your opponent's Pokémon equal to the number of damage counters on this Pokémon.