Mr. Briney's Compassion (POP Series 2 008/017)

Rules

You can play only one Supporter card each turn. When you play this card, put it next to your Active Pokémon. When your turn ends, discard this card.

Choose 1 of your Pokémon in play (excluding Pokémon-ex). Return that Pokémon and all cards attached to it to your hand.