Kublai Khan was a chinese djinn who lived in the 13th century. He was transubstantiated from the golden tablet by Iblis when he tried to use it for evil and later imprisoned him and Rudyard in their jade suits. He then gave Philippa her own Gestalt slippers.
Kublai was concerned about the risk that the Dong Xi posed to the future generations so he asked the Blue Djinn to visit him. It was the Blue Djinn's idea to create five golden tablets of command using Kublai's own fingernails in the smelting of the gold so that his spirit could be summoned again by her powerful binding.