Your castle, the majestic Castellion, is the last line of defense against the dread Menace, an entity that wants nothing more than to ravage everything in its path. Before you face the Menace itself, you must prepare your shape-shifting fortress by positioning its chambers into the best defensive formation. In Castellion, one or two players collaborate to ward off the Menace—constructing stout bastions, erecting mighty towers, and preparing lines of defense. Place your tiles or discard them to activate their special power and reshape the castle as you see fit. The more formations you form, the stronger your defense will be. Yet that is not all; to achieve victory, you must also overcome three Ordeals. Traitors are everywhere and discovering each one brings you closer to your next Ordeal. Fortify your walls and prepare for the Menace!