Mimighoul monsters you control that were not Normal or Special Summoned this turn gain ATK equal to their original DEF. Any player who controls a face-down monster cannot Normal Summon monsters, nor declare an attack with monsters that were Special Summoned this turn. During your Main Phase: You can add 1 Mimighoul monster from your Deck or GY to your hand. You can only use this effect of Mimighoul Dungeon once per turn.