Involuntary Cooldown is a uncommon Sorcery card from The Brothers' War (BRO), collector number 53. Current market price: $0.17 (foil $0.24), TCGplayer market prices via Scryfall.
Tap up to two target artifacts and/or creatures. Put two stun counters on each of them. (If a permanent with a stun counter would become untapped, remove one from it instead.)