Koa'ki Meiru Guardian (RGBT-EN023) - Raging Battle 1st Edition

During each of your End Phases, destroy this card unless you send 1 Iron Core of Koa'ki Meiru from your hand to the Graveyard or reveal 1 Rock-Type monster in your hand. You can Tribute this card to negate the activation of an Effect Monster's effect and destroy that monster.