Enkidu: Chains of Heaven (天の鎖エルキドゥ, Ten no KusariErukidu?) is the Noble Phantasm most trusted by Gilgamesh, even more so than Ea, and the "greatest secret" stored in the Gate of Babylon. It is a chain named after his closest friend made to bind the gods so they cannot escape, making it one of the few Anti-Divine weapons that holds the concept of "reigning over the gods." The strength and durability of the chain grows stronger with the target having higher Divinity, but is no more than a tough chain to a target without Divinity like Saber, Assassin, or Archer. When used against a regular human like Shirou Emiya, he feels he has no chance of prying it off of him. Divine targets are completely held in place, allowing him to bind the "Bull of Heaven" that brought seven years of famine in Uruk.