Gilgamesh served as Kotomine's Servant during the fourth Holy Grail War where he was known as his Servant class, Archer. He doesn't serve Kotomine as a Servant, but rather as his partner. Gilgamesh is arrogant, egomaniacal, and megalomaniacal. He considers himself superior to everyone else and places himself above even gods. Gilgamesh has a special ability to act independently and to completely ignore his Master's orders.
Typically clad in an ornate golden armor, he possesses an immense number of Noble Phantasms, though none are representative of his true identity. Because of this, no one could identify his true name. Gilgamesh met Saber during the fourth Holy Grail War and developed an obsessive interest in her.
Gilgamesh is a 2/3 god and 1/3 human king who ruled the Sumerian city of Uruk (in Mesopotamia, present-day Iraq) in 2600 BC. He was the king of heroes whose tale is recorded in mankind's oldest surviving recorded epic poem, "Epic of Gilgamesh".
Gilgamesh was originally a tyrant who did not care for his people. The Goddess Aruru created Enkidu in response to the prayers of the people to befriend Gilgamesh. Gilgamesh recognized Enkidu as an equal they ruled the city fairly.
Gilgamesh and Enkidu defeated Humbaba, guardian of the forest and beast of the gods, and became the greatest and richest king on Earth. Ishtar, the goddess of fertility, fell in love with Gilgamesh. He rejected her because he knew her as unfaithful, cruel, and a corrupter of men.
Ishtar was infuriated and wanted revenge. She requested her father Anu to unleash the Bull of Heaven. It caused 7 years of starvation and destruction on earth. Gilgamesh and Enkidu managed to defeat it, further propelling his reputation and crushing Ishtar's reputation.
Ishtar then requested that Enkidu be struck down for killing a beast of the gods. Gilgamesh was shocked that Enkidu, whom he sees as an equal, could die. He was tormented by the fear of death and he traveled to the Netherworld to find a way to defy death.
After the long and arduous journey, Gilgamesh managed to obtain the elixir of immortality. On the way back, the elixir was stolen by a snake and Gilgamesh died of grief. It is said that the snake drank the elixir, shed its skin, and began a new life.
Fourth Holy Grail War
Gilgamesh and his Master Kotomine and Saber and her Master Kiritsugu were the last 2 participants of the war. The Holy Grail had almost completely manifested and Kiritsugu ordered Saber to destroy it. The vessel shattered, spilling its tainted contents on Kotomine and Gilgamesh.
Gilgamesh managed to resist the taint and he was given a physical body and reincarnated into the world. He hid with Kotomine and subsisted on the souls of the orphans of the war. He waited until the fifth Holy Grail War to gain more power from a completed Holy Grail and to carry out his ambition to rule the world which he claimed as rightfully belonging to him.
Gilgamesh was first seen talking to Sakura outside her home. He appears to be threatening her before leaving. Neither Rin nor Archer have seen him before and Archer could not identify him as a Servant.
Gilgamesh was first seen when Caster attacked Shirou's home. He struck her down quickly with several showers of swords and announced that he will acquire Saber for himself.
Later, Gilgamesh ambushed Shirou and Saber after their date. Gilgamesh easily overpowered Saber's Excalibur with his Enuma Elish and severely damaged her. Shirou then projected Avalon to defend against his second Enuma Elish which shocked Gilgamesh. He retreated after that allowing Shirou and Saber to retreat as well.
The next day, Gilgamesh killed Lancer for allowing Shirou and Saber to escape from the church. Soon after that, he attacked Shirou's home, injured Rin and kidnapped Illyasviel. That night, Gilgamesh was defeated by Saber at Ryudou Temple.
Unlimited Blade Works
After Shinji lost his Servant Rider, Kotomine allied him with Gilgamesh. He voiced his desire to obtain the Holy Grail and realized that Shinji knew nothing about the Holy Grail. They assaulted the Einzbern castle where Gilgamesh defeated Berserker and ripped Illyasviel's heart out being the vessel of the Holy Grail. He then implanted it into Shinji, turning him into a Holy Grail.
Gilgamesh later tried to open the gate of the Holy Grail at Ryudou Temple. Shirou dueled and defeated him within his Unlimited Blade Works. After the gate opened, Gilgamesh was sucked into it. He tried to use his chain Enkidu to pull Shirou into the gate as well but he was rescued by Archer.
Gilgamesh discovered the black shadow in town and attempted to kill it with a shower of swords. It managed to devour Gilgamesh which in turn fed the Holy Grail with more energy.
Ea is named after the Babylonian god of creation, originally known as Enki in Sumerian mythology.
Gilgamesh's preferred sword. Unlike the other weapons in his treasury, Ea is the only one of its kind. It is made from outer-worldly material. Ea is the most powerful Noble Phantasm. Its blade is made of 3 segments that spins in alternate directions.
Gilgamesh reserves the use of Ea only against the most powerful opponents. His arrogance occasionally causes him trouble where he could've wielded Ea to flat out destroy his target.
A magical chain that is used to bind a target.
Enkidu is named after Gilgamesh's best friend. It is more powerful against divine beings. Enkidu can also prevent a Servant from responding to a Command Spell summon. Against a target with no divinity, it is simply a strong chain.
Enkidu was used against Berserker and Shirou on the Unlimited Blade Works route.
Gilgamesh's golden armor is materialized using magical energy. It is extremely durable and is resistant to most attacks. He could guard against Saber's sword strikes by simply blocking with his arm. Saber managed to blast through his armor with a point blank Excalibur in her last duel against him.
Enuma Elish is named after the Babylonian creation myth.
Ea's magic attack. Unlike other Noble Phantasms, Enuma Elish is activated by chanting the name of the attack instead of the weapon.
Ea charges up its attack by spinning its blade, absorbing the surrounding air. It then unleashes an enormous storm powered with magical energy.
Enuma Elish can easily overpower Saber's Excalibur. It can be defeated by Avalon.
Gate of Babylon
Gilgamesh's access to his entire treasury which contains everything that he has acquired in his lifetime. He opens it with a key in the shape of a short sword.
The gate can opened at any size and position. He can summon a sword into his hands or to land a precise attack on his target.
Gilgamesh is most famous for showering swords on his target. The swords can be immediately returned to the treasury after being launched. This ability classes him as an Archer because the swords are used as projectiles.
During Gilgamesh's lifetime, he managed to acquire all the world's most powerful weapons. Because of the sheer number and variety of weapons at his disposal, his opponents will face extreme difficulty in fighting against him. Each weapon is a Noble Phantasm in itself and embodies the level of power and special ability that its reputation entails.
The weapons that he possesses are actually nameless. They are prototypes that later became Noble Phantasms of heroes that came after him. However, there are certain Noble Phantasms that he does not own, like Saber's Excalibur which was crafted and given to her after Gilgamesh's time.
Gilgamesh greatly dislikes Shirou and Archer for their ability to project copies of his weapons, calling them "fakers".
These are weapons from Gilgamesh's treasury that has been identified.
The demonic sword of the sun, Gram.
Gram is the sword of Sigurd, the greatest hero of Norse Mythology and featured in the Volsunga Saga. "Der Ring des Nibelungen" was composed in Middle Ages Germany about a hero who is equal in status to King Arthur who wielded this very same sword. In that story, the sword's name was Balmung.
It is the prototype of Saber's Caliburn.
The holy sword of Roland, paladin of Middle Age Europe.
King Charlemagne was given the sword by an angel which he awarded to Roland, leader of the 12 knights.
It holds 3 miracles and it does not lose its sharpness.
A holy sword wielded by Perseus, the hero of Greek mythology.
The sword itself is not very powerful, but it has the special ability to nullify the special ability of immortals, and the wounds inflicted by Harpe cannot be healed.
It was used to kill Medusa, the youngest of the 3 Gorgon sisters.
One of the divine symbols of Indra, leader of the Devas and the god of war and lightning in the Hindu mythology.
Indra was originally a phenomenon introduced by the Aryans, and Vajra was called Vijya.
In Buddhism, Indra was named Taishakuten and Vajra had a different name.
A demonic sword featured in Norse mythology and "Der Ring des Nibelungen". It is a cursed sword that brings ruin to its wielder.
The sword was handed down through the family that killed Sigurd and it was originally possessed by the dragon Fafnir.
A halberd which was later identified to belong to Lu Bu of the Chinese Three Kingdoms Period.
A halberd can be used to thrust, swipe, pull, and parry, but it requires a great deal of skill to wield effectively. It fell out of favor but returned during the Sung period.
This particular halberd was promoted to the status of Noble Phantasm because of its wielder Lu Bu.
The signature weapon of Cu Chulainn, the greatest hero of Irish mythology.
A cursed red lance that inflicts wounds that cannot heal as long as the weapon exists in the world.
It has the ability to guide itself to pierce its target's heart.