Stronghold the Moving Fortress - LCYW-EN101 Ultra Rare 1st Edition

Special Summon this card in Defense Position as an Effect Monster (Machine/EARTH/Level 4/ATK 0/DEF 2000). (This card is also still a Trap.) While you control "Green Gadget", "Red Gadget", and "Yellow Gadget", this card gains 3000 ATK.