A strong Ghoul that glows with a dark aura and attacks by moving at great speed, unlike that of his brethren. He is much more difficult to kill than the other ghouls. He only appears when all ghouls in a room in the 13th Street have been cleared, sharing this particularity with the Wight and Zombies.
Finding and defeating the Ghoul King is required in order to complete Wind's quest: "Defeat the Ghoul King". Travel to the 13th Street and look for a certain room infested by Ghouls. Start killing them, preferably staying on one side of the room to make the king appear on the other end and have more time to kill him once he finally appears.
One method to defeat him consists simply by casting 1,000 Blades at him; otherwise, Slash, Fire, or Holy weapons such as the fully-powered Vampire Killer or the Holy Claymore should also make short work of him. Once he's dead, return to Wind in order to receive the Immunity Ring.