Commander Olrox is one of the commanders serving under the vampire queen, Carmilla. Like his brother, Lieutenant Brauner, he is a vampire of demonic origin rather than human; the two brothers having previously been demons lurking the depths of Hell before somehow being summoned to Earth by Carmilla and made into vampires. They rule from the Bernhard family castle.
Olrox fights Gabriel in single combat inside the Bernhard Castle in a last ditch effort to stop him from reaching Carmilla in the throne room. Despite being a very strong opponent (and despite feeding from the various Lycan corpses found in the room to regain his strength), he is eventually defeated by Gabriel, who slits Olrox's throat with his own sword and uses his spilled blood to solve the puzzle required to open the door leading out of the room.