TV-Series
Description
Gilgamesh exists as the Heroic Spirit sealed within the eighth Class Card, an anomaly beyond the initial seven gathered during Miyu Edelfelt's ritual. Displaced deep within the Earth's pulse during its interdimensional transfer, this displacement enabled his partial incarnation. Unlike the fully corrupted and mindless spirits within other Class Cards, his immense ego grants partial resistance, manifesting his younger self rather than his adult Archer form. This half-incarnated state results in a childlike appearance, retaining his golden hair and red eyes, typically worn down, resembling a youthful version of his adult casual form. He initially wears ancient-style clothing, later adopting modern attire upon arriving in Miyu's world.

Personality-wise, this incarnation displays a more easygoing and conversational demeanor compared to his archetype, engaging potential adversaries when interests align, such as aiding Illya's group against threats like the Ainsworths. However, core arrogance and vanity surface situationally, especially in combat—evident in his trademark insult "mongrel" directed at Angelica for wielding Enkidu's power. He strategically withholds critical knowledge about Miyu, the Ainsworths, or Kirei Kotomine, revealing a calculated, observant nature. Despite allying with Illya in 3rei, his motivations remain self-serving, primarily focused on reclaiming his Noble Phantasms stolen by Angelica.

His role begins during the 2wei arc as the eighth card destabilizes Fuyuki's ley lines, absorbing energy for months and growing stronger than previous spirits. After resisting a joint assault by Illya, Miyu, Kuro, Rin, Luvia, and Bazett, his corrupted shadow form escapes the Mirror World using Ea and Vimana, seeking Mount Enzou's Holy Grail site to complete incarnation. Illya inadvertently separates his conscious younger self from this shadow during a confrontation. Following a temporary fusion into an Angra Mainyu-like monstrous form, Illya defeats him using the combined Kaleidosticks (Zwei Form), reverting him to his younger self and freeing Miyu. He reveals his half-incarnated state weakened Ea's output, contributing to defeat.

In 3rei, he reappears as a deuteragonist after Illya enters Miyu's parallel world, forming a reluctant alliance with her and Tanaka against the Ainsworths, driven by Angelica's use of his Class Card to usurp control of Gate of Babylon, severely limiting his treasury access. His battle with Angelica demonstrates tactical superiority and mastery over Enkidu, though he retreats upon her deploying multiple Class Cards. Later, he aids Bazett in freeing Rin, Luvia, and Shirou Emiya from Ainsworth captivity. During the final confrontation, he extracts his Class Card from Miyu—briefly succumbed to its influence—using Enkidu, regaining full power. After effortlessly defeating Beatrice, he discerns Julian Ainsworth's plan involving a massive mud cube (Pandora's Box) and Erika's nature as a virtual phantom. Amused yet disinterested in direct intervention, he departs as a spectator, noting the need for multiple Holy Grails to achieve Julian's goal.

Abilities in his half-incarnated state are constrained. While connected to Gate of Babylon, it contains only minor Noble Phantasms and items, lacking most treasures. Full access requires merging with his corrupted shadow or reclaiming weapons stolen by Angelica; he retrieves 264 via ownership reversion. The corrupted shadow form employs a mist-like body for instant regeneration and weapon deployment, surviving card extraction attempts by absorbing the card internally. Key Noble Phantasms include Ea (used to breach dimensions), Enkidu (chains effective against divine entities), and Vimana (airship).