Xanxian, Ancient Beast of the Dunes is an extremely powerful Fire Elemental who is willingly bound to the Fortress of the Black Lion. He appears to be made out of sand and can change his shape at will. His most common form is that of a massive lion with eyes, teeth, and claws made of adamant and a burning mane and tail. He also has the power to redirect the Essence vents of the Fortress without disrupting the manse's geomancy.
Xanxian, or Xan as he prefers to be called, is a rather stoic soul. He guards the Fortress with pride and, as he often emphasizes, was willingly bound to it at the time of its creation, although he doesn't recall who built the manse or bound him. He and Shahra seem to know each other quite well, though they don't show it.