King Castle appears in the first World of Magatsu Mandala within the Midnight Channel. It is a shadow that attacks using only Physical skills. King Castle is Weak to Light and Darkness skills and takes 50% more damage from Fire, Ice, Electricity, and Wind skills. After being defeated, it may drop a Snow Stone. Selling 4 Snow Stones will unlock the Hero Legs for Chie Satonaka in the shop.
In Golden, King Castle appears in Magatsu Mandala Worlds 1 to 3. It is solely a physical attacker, protecting its weakness with Dodge Fire, and can increase its critical rate using Rebellion. It may drop Rainbow Quartz for trade at Shiroku Pub.
King Castle appears on Blocks four and five of the Theater District. It attacks with multi-hit Physical attacks, can Hex the party, and can increase its strength with Tarukaja. When defeated, it may drop Castle Cache and Castle Bell. Castle Cache is used to create the Megaton Rod for Ryuji, the Shizuka for the P3P heroine, the Pinaka for Ken, the 7-Star Claw for Teddie, the Black Hole for Naoto, and the Hallowed Plate armor. Castle Bell is used to create the Amazon Axe for Haru.