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, Ornstein guarded the Anor Londo cathedral alongside Executioner Smough.
At some point, Ornstein left the cathedral in search of the Nameless King. It is unclear how Ornstein survived the battle against the Chosen Undead, but it appears that he eventually found his way to Archdragon Peak. However, the results of his search, as well as Ornstein's own fate, remains unknown.
- Ornstein appears in Dark Souls II as the optional boss Old Dragonslayer, using a black armor instead of the original gold, as well as using dark powers instead of lightning. They are confirmed to be the same person in the Dark Souls II Collector's Edition Guide.
- The Leo Ring and Ornstein are homages to famous Russian-American composer, Leo Ornstein, an experimental composer of the early 20th century.