Ereshkigal serves as the Sumerian Goddess of the Underworld, tasked since birth with administering the realm of the dead. Confined solely to the underworld throughout the Age of Gods, she never experienced the surface world or freedom. Her duties encompassed overseeing the growth and decay of crops, controlling underworld familiars such as dragons and snakes, and imprisoning souls using her spear-like cage weapon. This spear functioned as both a combat instrument and a soul confinement tool, capable of summoning lightning during attacks. Her Authority facilitated various attacks and security measures essential to governing the underworld. Mythologically, Ereshkigal represented human death as the Terrible Earth Mother, forming a natural contrast and rivalry with her sister Ishtar (Inanna), the harvest goddess symbolizing human life. In the tale of Ishtar's descent, Ereshkigal killed Ishtar upon her visit to the underworld, though the specific reasons for the visit or Ereshkigal's rage remain unspecified. Within Fate/Grand Order's narrative, their conflict stems from interpretations of them as either two equivalent existences or a single divinity divided into separate entities. Manifesting as a Pseudo-Servant, Ereshkigal inhabits the soul of a compatible human, Rin Tohsaka. Unlike Ishtar, who shares Rin's standard appearance, Ereshkigal manifests with blonde hair, resembling the version of Rin Tohsaka seen in Fate/EXTRA, reflecting her underworld association rather than surface-world attributes. Personality-wise, Ereshkigal presents as passive, introverted, and bound by the pride and wisdom inherent to her role as mistress of the dead. She historically embodied envy and brutality, desiring to possess what she coveted and eliminating anything she could not obtain. Assimilation with her human vessel instilled greater self-awareness, causing her to perceive these tendencies as embarrassing and inappropriate. Consequently, her more ruthless aspects receded, though they may resurface when angered, aligning with her fearsome mythological depictions. Despite claiming disinterest in humans and finding living beings "sickening," she harbors a caring nature, expressed through concerns about underworld overcrowding and desires to improve conditions for souls. Her speech patterns combine theatrical elocution similar to Ishtar's with occasional outbursts of panic or honesty, reflecting an underlying courteous demeanor. During the events of Babylonia, Ereshkigal joined the Three Goddess Alliance against Uruk. Her motivation stemmed from a wish to protect human souls within her realm, Kur, driven by a love for humanity and a desire to safeguard those fated to die. She resented being universally feared as a villain despite recognizing the necessary role of death. Secretly, she envied Ishtar's freedom and yearned for acceptance as the underworld's mistress without prejudice. This period revealed her annoyance at Gilgamesh's casual underworld visits, wariness toward Enkidu's perceived danger, fear of Quetzalcoatl due to past conflicts, and an acknowledged sense of affinity with First Hassan and Nitocris despite lacking formal acquaintance. Her abilities include the Noble Phantasm Kur Kigal Irkalla, an Anti-Mountain attack damaging all enemies while providing supportive effects to allies marked by her Blessing of Kur status. This blessing, applied via her third skill, enhances defense, NP generation rate, and maximum HP. She wields additional skills: Mana Burst (Cage) accumulates mana for Buster performance boosts and NP charging, while The Secret Great Crown grants invincibility alongside chances for debuff immunity, instant-kill immunity, and buff removal resistance.