If a face-up Rock monster you control is sent to the GY (except during the Damage Step): You can Special Summon this card from your hand. If this card is Special Summoned: You can add from your Deck to your hand, 1 "Iron Core of Koa'ki Meiru" or 1 card that mentions "Iron Core of Koa'ki Meiru", except "Koa'ki Meiru Supplier". You can only use each effect of "Koa'ki Meiru Supplier" once per turn.