[Auto]<Valid> Square <Trigger> This card appears. <Effect> If there are 4 or more [Metal Fortress] in your Resource, reveal 4 cards from the top of your deck, choose 1 [Metal Fortress] among them, add it to hand, return the rest of revealed cards back, and shuffle, choose 1 of your [Metal Fortress] on Square, and give it following ability until end of turn. " [Always]Absolute Boundary (This card cannot be chosen as the target for a card's effect by anyone.)"