. . "Cloudland Keep is Lady Opal's stronghold atop Shimmer Mountain in Overlord: Minions. This is where crystals extracted from the mountain caverns are brought. The Keep is neither fortress nor tower, rather half monastery and half castle."@en . . "Cloudland Keep is Lady Opal's stronghold atop Shimmer Mountain in Overlord: Minions. This is where crystals extracted from the mountain caverns are brought. The Keep is neither fortress nor tower, rather half monastery and half castle."@en . . "Cloudland Keep"@en .