Klefki (Steam Siege STS 80)

Klefki — 70 HP — [Y]
Basic

Ability: Wonder Lock
Once during your turn (before your attack), if this Pokémon is on your Bench, you may discard all cards attached to this Pokémon and attach it to 1 of your Pokémon as a Pokémon Tool card. Prevent any damage done to the Pokémon this card is attached to by attacks from your opponent’s Mega Evolution Pokémon. If this card is attached to a Pokémon, discard this card at the end of your opponent’s turn.

[Y][C] Fairy Wind: 30

weakness: [M]×2
resistance: [D]-20
retreat: 1

Illus. Saya Tsuruta
Steam Siege — 80/114 — Uncommon

It never lets go of a key that it likes, so people give it the keys to vaults and safes as a way to prevent crime.