Mimighoul Dungeon (Quarter Century Secret Rare)

"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.