A King Vessel (王の器, Ō no Utsuwa), formerly known as a King Candidate, is a Dungeon Capturer that is rewarded with a Djinn. This person is chosen as the King Vessel regardless if they are led by a Magi, despite the Vessel’s lineage or status. The right King Vessel chosen is to be the next Solomon.
Each of these King's Vessel's had entered and successfully conquered their respective Dungeons without the company of a Magi and as such it is unknown which of the Four (Five) current Magi's had raised their respective Dungeons.