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He loathes the thought of having to seriously use it against Shirou for a second time once inside Unlimited Blade Works. He becomes enraged when Tohsaka Tokiomi even suggests that he use it to defeat the creature summoned by Caster. Rider is accepted as a worthy opponent during the Fourth Holy Grail War, and Ionioi Hetairoi is considered a stage befitting its usage. He claims that only Saber and her Excalibur are worthy of fighting it during the Fifth Holy Grail War. While he uses it against Shirou Emiya solely for the fun of showing off his treasure, he claims that he does not want to sully the sword against a lowlife for when he uses it against those he truly recognizes as fitting. Gilgamesh considers it his greatest and most trusted treasure next to Enkidu, one of the few esteemed treasures, which is only used against those he deems worthy of facing it.
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Everything together represents the universe. The " cosmos" is thus represented by matching all three of these representations. It exemplifies the world's way of being by having each one of them rotate in opposite directions. Its three sections respectively represent the heavens, the earth, and the underworld. While Ea is categorized as a sword, its way of being is closer to a wand. The drill design was modeled after bedrock excavators used to drill underwater tunnels. It has the shape of a cylindrical, drill-shaped pillar made up of three independently rotating segments engraved with crimson cuneiform lettering that spin slowly in an alternating direction like querns, the middle segment spinning clockwise and the top and bottom segments spinning counterclockwise. The " blade" itself and the tip of the sword, spun in a spiral shape, are dull. While it has a grip, handguard, and is the same length as a longsword, the section that should contain a blade deviates from the normal form of an edged weapon. It is something that was born before the appearance of the concept that the world calls a " sword," so it is not something that can truly be called a sword or have the shape of any known blade. It has an abnormal shape that doesn't match what would normally be classified as something specialized like a sword. It can be used as a close combat slashing weapon wielded much like a regular sword as shown in Fate/unlimited codes, and even with its dull tip, it can pierce directly through Rider's chest. Rider comments that the nature of the sword becomes more absurd as he views its power. Unlike all of his other nameless weapons that were able to be passed on to other wielders throughout history, it is a sword only Gilgamesh possesses, a unique existence that can only be possessed by him, that is suited only for a ruler's use and makes him transcendent.
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Sword of Rupture, Ea (乖離剣・エア, Kairi-ken - Ea ?) is the most powerful Noble Phantasm contained in the Gate of Babylon and the pinnacle of all those used by Servants.
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