Once per Chain, during the Main Phase, if a Mimighoul monster your opponent controls is flipped face-up: You can randomly choose 1 face-down card in your opponent s Extra Deck, and if it is a monster that can be Special Summoned, Special Summon it to your field, but it cannot activate its effects this turn. If it wasn t, or couldn t be Special Summoned, banish that card. You can only use this effect of Mimighoul Charm twice per turn.