Gilgamesh takes a very easygoing attitude to the events of the Ainsworth's Holy Grail War, talking quite conversationally even with those that could be considered his enemies. Though not an ally, he works with Illya's group so long as their objectives coincide. He likes to make sport of the others, acting aloof even during their more serious discussions. He knows much about the situation that he has not let on to them, involving meeting Shirou, having knowledge of the Ainsworths and Miyu, knowing of Kirei's situation, and something hidden about his very existence. Even he is surprised in being separated from his other half by Illya, but decides the "most natural" action is to merge with it to fight her with all his strength while telling her to strike down his pathetic self. He displays a more sarcastic and sadistic personality when first fighting Angelica, partly due to her using his "friend", Enkidu.
The corrupted Gilgamesh is mostly mindless like the other corrupted Heroic Spirits, but mentions seeking out the Holy Grail and wishing to complete the ritual much like those summoned by Julian's object.
Contrary to Miyu Edelfelt's knowledge that there should only be seven Class Cards for the ritual involving her, Gilgamesh was infused into an eighth card for an unknown reason. Unlike the other cards that were transferred to more accessible areas, his card was placed deep into the Earth, lost on the way to the "boundary of the real number region" between the two worlds.
Fate/Kaleid Liner Prisma IllyaEdit
Fate/Kaleid Liner Prisma Illya 2weiEditThe eighth Class Card that holds Gilgamesh is identified as being the reason for the continued disruption in the center of the Earth Pulse in Fuyuki. It has continuously absorbed energy for the two and a half month period, considerably shrinking the Earth Pulse in proportion and becoming stronger than any of the previous heroes. Located deep underground, it requires much excavation just to reach the point to enter the Mirror World. Illyasviel von Einzbern, Miyu Edelfelt, Kuro, Bazett Fraga McRemitz, Luviagelita Edelfelt, and Rin Tohsaka all prepare to face it with all their strength to finish it off at once. Luvia binds it, Rin creates a magic amplification circuit to enhance the power of Illya and Miyu's strike, and Kuro subsequently uses Excalibur as a Broken Phantasm. The Shield of the Gods easily blocks, making them realize it is beyond their capabilities.
Bazett decides to take action, charging towards it only to be gouged by many weapons from the Gate of Babylon. Able to proceed forward with a rune of resurrection, she can do no lasting damage to it due to the mist-composition of its body. It launches a full-scale attack, requiring Kuro to use Rho Aias for protection, while Bazett uses three Fragarach and charges through the rain of swords. Unable to make it before receiving a fatal attack to the head, she is saved by Kuro and given the chance to rip the card from its heart. Due to its power, it is able to take the card into itself, and as it calls out for the Holy Grail, brings out Ea. Feeling the primal fear from its ability, they escape before being caught up in it.
It manages to escape from the Mirror World through a crack in the space caused by Ea, causing Luvia to collapse the excavation site to bury it as they escape. It uses Vimana to escape ahead of them, easily plowing through the collapsing rock. Floating listlessly in the air for a time, it displays a clear intent not shown by the other heroes, starting to move towards the ritual site of the Holy Grail at Mount Enzou. Excitedly dropping weapons to expose the cavern within, it lands on the ground and activates a massive magic circle within it. Signs of the incarnated half of Gilgamesh begin to show on his body, and Illya, unable to stop him with magical attacks, physically attacks and inadvertently pulls him out.
After Illya talks with his younger form, Miyu attacks him before the shadow breaks through the barrier and grabs her to use as a vessel for the Grail. Leaving Illya with both Kaeleidosticks and the younger Gilgamesh.
After the barrier vanishes, he fuses once again with his shadow, becoming an incarnation of darkness not unlike Angra Mainyu. He battles Illya for a short time before she is supported by Kuro and Bazett. Gilgamesh then goes for a killing blow with a massive sword which Illya counters by taking her 2wei form. Recognizing her as a worthy opponent, he laughs and starts drawing more weapons.
He eventually draws Ea in order to finish the battle, but is overcome by a enormous volley of fire from Illya, which cuts apart the shadow form reducing it back to the younger version and Miyu. Gilgamesh declares that he was only able to half-incarnate, explaining the attack of Ea being overpowered.
Fate/Kaleid Liner Prisma illya 3reiEdit
Gilgamesh returns in the third series as a protagonist. After Illya finds herself trapped in Miyu's world, she is found by Gilgamesh, who quickly charms her into a reluctant alliance against the Ainsworth Family, who were behind the strange figures that kidnapped Miyu at the end of 2wei.
As the small group infiltrates the Ainsworth castle, they are attacked by the family's "Dolls", and Gilgamesh reveals his true motivation for opposing them: one of the Dolls, Angelica, is utilizing his Class Card to claim the majority of Gate of Babylon, severely limiting Gilgamesh's own powers. He enters into battle with Angelica, each of them utilizing their own Gate of Babylon in an attempt to claim the entirety of the Noble Phantasm for themselves.
Gilgamesh is an anomaly compared to the other Class Card Heroic Spirits in that he is separated from the Class Card and becomes half-incarnated. It is due to his ego being stronger than that of other Heroic Spirits, allowing him to partially resist the normal way the Class Cards crush their wills and personalities. He could potentially take over a person using the Archer Card poorly, and Bazett claims there is also more to his existence that he refuses to explain. The other half remains like the other corrupted Heroic Spirits, without reason and deranged until being resealed in the Class Card and used by Angelica.
He calls himself a mere shadow of his true self, and mentions that him being fully incarnated would have drastically changed the way the "story" played out. He is not properly connected to the Gate of Babylon in his form, and though he can use it, it lacks most of his treasures, and only contains minor Noble Phantasms and items. He temporarily regains use of them by merging back into his other half, but they remain with the Class Card after it is sealed. He is able to retake weapons fired by Angelica's Gate of Babylon, allowing him to gather 264 weapons back from her. She is unable to do the same because the treasures remain under his ownership, so taking any treasures stolen from him and returning them to her own Gate of Babylon simply returns them to his treasury.
The main body of the Class Card-half of Gilgamesh is composed of a black mist similar to that wielded by Saber, although on a different magnitude. Rather than use the Gate of Babylon its normal way, it spreads the mist over the ground to deploy weapons, both levitating swords before firing and simply striking from below the opponent. Its body is extremely durable, as any damage inflicted is restored instantly by the mist. The mist is able to be manipulated in a way so as to act as its sword and shield, displays enough dexterity to hold and strike with weapons, and it can be spread out as tentacles to push opponents away. Differing from the other Heroic Spirits, it is able to survive having the Class Card at its heart removed and recollect it using the mist.
After arriving at the ritual site, it activates a magic circle that forms a vortex, and it emerges as a massive, spider-like form that is "bloated with madness." It can easily wield the massive Ig-Alima and Shield of the Gods as melee weapons, and made of the same black mist as its original body, summon weapons and shields from any part of its body. After Gilgamesh remerges with it, he is able to control it to fight Illya. After it is defeated, it returns to the card while still leaving Gilgamesh in the world.
Gate of BabylonEdit
The Gate of Babylon possesses all the treasures of the world, including all Noble Phantasms. It is strange to him that he does not know of Apneic Beauty and Authoritarian Personalism. He could understand if they were minor Noble Phantasms, but such powerful ones should be easily known to him. The contents are split between himself and the Class Card, with either side able to take the contents into their own Gate of Babylon. It contains many minor fineries like clothing, books, gold and gold coins to purchase items, jewelry, and furniture.
- The Arrow-avoidance amulet is a D- rank charm that negates any projectile weapon below D rank. It brings about a translucent rectangular shield, and it can also be used as a walkway in the air. It can be destroyed to imitate a fragment of the Sun that can grow and hit a target with a bit of the Sun's light and heat.
- The Cloth of Concealment (身隠しの布, ?) is the cap of invisibility owned by Hades. It is an E-rank Noble Phantasm, normally kept in the form of a sash, that uses optical magic to block all forms of magical detection and magical emanations from the wearer. It does not obscure sound or smell, so the wearer is not protected from people smelling or hearing them up-close. While it its sash form, it can be held by multiple people at once. It can wrap itself up automatically to return to its hat form.
- Ea is Gilgamesh's trump card and most powerful weapon. It is able to tear through the Mirror world and the boundary to Miyu's world. Though it loses to Illya's final attack, he mentions that it was the best he could do while half-incarnated.
- Enkidu is Gilgamesh's most trusted Noble Phantasm. He is outraged by Angelica's usage of it, and he is able to take it from her. He displays great control over it, allowing him to take a large number of weapons from Angelica into his own Gate of Babylon, take people to safety, and use it as a shield to deflect the thrown Mjolnir.
- The Hot Spring Noble Phantasm is able to be established anywhere, even the roof of a building. He is able to modify it to fit Japanese customs.
- Sul-sagana (シュルシャガナ, ?) is a large, jagged sword that launches a beam-type attack. It is named after a deity in Sumerian mythology.
- The Shield of the Gods (神々の盾, ?) is a massive, ornate dome-shield used to block an extremely powerful magical attack and Kuro's Excalibur without a scratch. It is destroyed by Illya in her Zwei Form.
- True Nine Lives