The strongest Noble Phantasm of Gilgamesh and known to Fate/Stay Night. It's attack Emuma Elish can tear apart the surrounding space, leaving a void of destruction.
Ea is the most powerful Noble Phantasm contained inside Gilgamesh's Gate of Babylon. This is one of the few Noble Phantasms that truly represent Gilgamesh. Its attack generates a fake layer of space to violate the rules of reality with a power far surpassing Excalibur. It is considered his greatest treasure, only using it against those he deems worthy, and his most trusted next to Enkidu.
The sword has no name, it's said that the weapon existed before the creation of the world. Gilgamesh have acquired it in his journey to the Netherworld by chance. He named it Ea after the god of water and magic, the shaper of the world in the Sumerian mythology. It is a cylindrical, drill-shaped sword engraved with crimson cuneiform lettering on three independently rotating segments that spin in different directions. It is similar to spear crossed with a bedrock drill designed with multiple gears to dig a gigantic hole by eating at the bedrock little by little. Its material components have no origin on the mortal plane, and thus, Emiya Shirou is unable to trace it.
Gilgamesh charging Ea
Ea's attack, the Star of Creation that Splits Apart Heaven and the Earth. Gilgamesh named it after the Sumerian creation myth. While Excalibur releases air, the triblade segments of Ea start rotating rapidly, creating a shrilling howl, on Gilgamesh's command, once telling it to "wake up", and begin to swallow, compress, and accelerate wind pressure. This wind is compressed into an artificial space-time dislocation capable of pulverizing any opposition. The name of Enuma Elish is called for optimal output and the attack. While holding back, the general output of the sword releases a torrent of energy slightly greater than that of Excalibur but the maximum output causes a true distortion of space to be opened. Halting the laws of the universe with its power, it creates a rip that extends from the earth to the sky that pierces the world itself.
The "truth" showed by Enuma Elish.
It is a true "anti-world" weapon that opens an abyss capable of crushing all of creation and returning it to nothingness. The wind pressure creates a vacuum that takes all things with form, the land, and the sky into the whirling void leaving nothing but Ea shining like a star of creation looking onto a new world while signaling the end of destruction. The rift created by Enuma Elish is said to be a look at the "truth" of what existed before the world. Referring to it as hell, the primordial form of the planet before heaven and earth were split, a land filled with lava, gas, scorching heat, and intense cold, Gligamesh states that it is beginning of all legends of lands of the dead. It is the origin of the memory of all organisms before the existence of the planet that is no longer found in the imaginations or spoken memories of people, but rather a genetically inherent and repressed knowledge of a place and time when organic existence had been impossible.
On the course of story. Gilgamesh have seen to use Ea only a few times. In Fate he defeated Saber's Excalibur without effort and only shows defeat to Saber's ultimate protection, Avalon. In Unlimited Blade Works he uses Ea in anger to tear Shirou apart with a low-charge Enuma Elish. Shirou just barely survived it and later he quickly prevented Gil from releasing another such attack. He never used it in the Heaven's Feel route. In Fate/Zero Gilgamesh used Enuma Elish to completely obliterate Rider's Reality Marble alongside his summoned army.