Ornstein was one of Lord Gwyn's most trusted knights, and the first knight chosen by Lord Gwyn's firstborn. Believed to be the captain of the Four Knights of Gwyn, he was granted a special soul and ring by the Lord of Sunlight.
His golden armor was made to resemble a lion and is imbued with the power of lightning. It is said that his lugged spear could slice a boulder in two. After the gods fled Anor Londo, Executioner Smough guarded the Anor Londo cathedral alongside an illusion of Ornstein created by Gwyndolin. It is unclear how long it's been since Ornstein left, and it is uncertain whether he left when the Gods did, or if he left left long, long before, seeking Gwyn's firstborn after he was exiled. Ornstein's armor and spear are found in Archdragon Peak past the boss room. Whether he sought to kill Gwyn's firstborn for his betrayal, or to perhaps join him, and what became of Ornstein (whether he was killed or lay down his arms and disappeared) is unknown.
- The optional Old Dragonslayer boss from Dark Souls II is reminiscent of Ornstein, with the exception that his armor is gold and the Old Dragonslayer's is black.
- The Leo Ring and Ornstein are homages to famous Russian composer, Leo Ornstein, an experimental composer of the early twentieth century.