Ireopt, Diplomacy's Catalyst

Indestructible Peace— Whenever Ireopt, Diplomacy's Catalyst attacks or blocks, tap an untapped creature you control. If you do, target attacking or blocking creature gains indestructible until end of turn.

Mediation — At the beginning of your end step, if two or more creatures you control attacked this turn, choose up to one target creature controlled by an opponent. Until your next turn, that creature can't attack or block, and its activated abilities can't be activated.