Machina Peacekeeper (SBCB-EN072) [Speed Duel: Battle City Box]

When this card on the field is destroyed and sent to the GY: You can add 1 Union monster from your Deck to your hand. Once per turn, you can either: Target 1 Machine monster you control; equip this card to that target, OR: Unequip this card and Special Summon it. If the equipped monster would be destroyed by battle or card effect, destroy this card instead.