|“||Fighting against these chains is futile. Not even the gods themselves could break free of these chains.||„|
|~ Gilgamesh, about Enkidu|
Enkidu: Chains of Heaven is the Noble Phantasm most trusted by Gilgamesh, even more so than Ea, and the "greatest secret" stored within the Gate of Babylon in the Fate series. It is a chain that he named after his closest friend, which he uses to bind the gods so they cannot escape, making it one of the few anti-divine weapons holding the concept of "reigning over the gods." The higher the target's divinity is, the stronger the strength and durability of the chain grows, but nevertheless it's no more than a tough chain to a target lacking in divinity. Divine targets are completely held in place, allowing him to bind the "Bull of Heaven" that brought seven years of famine un Uruk. Since Gilgamesh is able to tell that the chain is not enough to completely bind the demi-god Heracles strengthened by Mad Enhancement, the chain does indeed have a limit.
Gilgamesh is able to take out the entire length of the chain from the Gate of Babylon to use it in conjunction with Ea when he is serious about fighting, or he can simply summon part of it from the gate. The chain can be summoned from anywhere the Gate of Babylon can reach, elongate and contract without any shown limit, and multiple sections can be summoned at one time. The blade on the front of the chain is capable of acting as a striking weapon when launched at a high speed, and he can summon a single length to wrap around a single opponent so he can drag them towards it by pulling it. Even against such targets as humans that have no divinity, it is still a Noble Phantasm nearly impossible to pry off once it has gotten a hold of them.
Once activating it as a Noble Phantasm, numerous segments instantly appear to wrap around the opponent in order to bind them for his projectiles. He generally binds the opponent's weapon, limbs, shoulders, neck, and abdomen, rendering them completely immobile. The chains continuously twist and tighten with enough force to attempt to tear off Berserker's head and bend his arms past their limits in a direction that is normally impossible. It appears to even bind the space around itself, and it is capable of rendering transportation ordered by a Command Spell, which is capable of magecraft close to that of True Magic, completely useless and nullified. It is possible, however, for a divine target to break the chain, such as when Berserker pulls off the impossible by using the last ounces of his strength. That doesn't actually destroy it, of course, as Gilgamesh later uses it again to grab the arm of Shirou Emiya.