Predaplant Banksiogre (COTD-EN016) - Code of the Duelist Unlimited

You can Special Summon this card (from your hand) by Tributing 1 opponent's monster with a Predator Counter. If this card is sent from the field to the GY: Place 1 Predator Counter on each face-up monster your opponent controls, and if you do, any of those monsters that are Level 2 or higher become Level 1 as long as they have a Predator Counter.