A knight in the caverns of Avalon.
Knight, an old title for a person that gave his sword and life in the service of others, to fight for them, or in the service of a cause or belief. It entitles the bearer to be addressed, in English, as 'Sir'.
Cameron Mitchell fought a holographic image of a knight in the caverns of Avalon, and won after having a tough battle. (SG1: "Avalon, Part 1")