Krizalid acts as the mid and final boss of The King of Fighters '99. He was designed to be a stylish and earnestly strong boss, though the supervising designer at the time admits, "I think I overdid it a little."He is made to be the ultimate Kyo clone, outfitted with a special suit to feed the data of fighters into his body during battle. He also happens to be a clone of K'. As a side effect, he gained some of K's memories and believed that Whip was his sister. He is ordered to activate the thousands of Kyo clones around the world so that they can attack in a simulatenous strike. After his defeat against K', his superior, Zero, neutralizes the Kyo clones and kills Krizalid by throwing a boulder to crush him. He is revived later by the original Zero and fights along side him in the 2001 tournament.
Source from Wikipeida