He is the founder and leader of the Order of Zugzwang, a religious cult who seeks to create the "White King's Paradise" to save everyone from the oncoming darkness. However, the cult is actually a front for the forces of Nadiria, controlled by Grandmaster Nimzo to invade the human world. King Korol oversaw for years the construction of the temple of Crocodilopolis atop Mount Azimuth, using enslaved humans to construct the temple over a demolished shrine. After the temple was concluded, many of the slaves were disposed of in order to hide their tracks, while the rest was brainwashed to serve the order.
The player reaches Crocodilopolis after restoring the Zenithian Dragon, finding the statue of his wife and a monster impersonating his mother. After defeating the monster, he invades the temple and confronts Korol. Upon being defeated, Korol pledges for Nimzo to help him, but Bishop Ladja appears and finishes off Korol, since he was of no use to The Grandmaster anymore.
He appears as an obtainable monster for the first time in Dragon Quest Monsters: Joker 2 Professional. Only released in Japan.