A holographic guardian is a security measure that Merlin was known to employ. The hologram, which took the form of a black knight, was capable of delivering harmful energy to an enemy through a sword, yet projectile weapons could pass through them. They can be projected over a long distance just like Asgard Holograms. The sword itself does not cut the opponent, but delivers serious physical pain.
The holograms also are capable of knocking people back making it (and the accompanying sword) the only known holograms to be able to interact with solid matter and become solid. Merlin had one in his vault in Avalon, to test the "worthiness" of any who would enter. He also had one guarding his library in Camelot. It is unknown if the rest of the Ancients used these but it is unlikely, although the solid hologram technology was most likely used in other Ancient bases for different purposes. (SG1: "Avalon, Part 2", "Camelot")
Behind the Scenes
- The knight was played by: Nicholas Harrison