Mordred, designated the Knight of Treachery or Saber of Red, exists as a homunculus clone of King Arthur (Artoria Pendragon). Morgan le Fay magically created her using genetic material obtained non-consensually from Artoria, temporarily rendered pseudo-male by Merlin. Morgan developed Mordred within her own ovary, resulting in accelerated growth and a drastically shortened lifespan. Raised secretly as Morgan's male heir to the throne, Mordred concealed her identity beneath a helmet provided by her creator. Her formidable combat skills and direct adherence to chivalry secured her a place within the Knights of the Round Table, despite her mysterious origins. Initially viewing Artoria as a "perfect king," Mordred harbored deep admiration. This devotion curdled into hatred when Morgan disclosed Mordred's true parentage, driving her to demand recognition as Artoria's heir. Artoria's rejection, citing Mordred's inherent lack of kingly capacity unrelated to Morgan, ignited rebellion. Seizing Artoria's absence, Mordred instigated the conflict culminating at Camlann. In their final duel, Rhongomyniad impaled Mordred; with her dying strength, she struck a fatal blow against Artoria. Typically summoned as a Saber-class Servant, Mordred can also manifest as a Berserker due to her enmity with Morgan. She wields Mana Burst to augment strength and agility, fighting with chaotic ruthlessness. Her Noble Phantasms include Clarent, the royal sword; Secret of Pedigree, her identity-concealing helmet; and Clarent Blood Arthur, an anti-army attack requiring helmet removal. This technique channels her fury towards Artoria, dealing amplified damage to targets bearing the "Arthur" trait. During the Great Holy Grail War (*Fate/Apocrypha*), Master Kairi Sisigou summoned Mordred. Their shared headstrong natures forged an alliance. Mordred sought the Holy Grail to validate her worth and right to rule by pulling Caliburn from the stone. Following Sisigou's death, she chose dissolution over seeking a new Master, honoring their bond. In the Solomon Singularity, Mordred was autonomously summoned among Heroic Spirits aiding Chaldea against Goetia. She contributed to the collective defense against Demon Gods and engaged Goetia directly alongside Servants like Nero Claudius and Jeanne d'Arc before being unsummoned. Mordred embodies pride and battlefield brutality, vehemently rejecting discourse on her gender. Her feelings towards Artoria intertwine volatile love and hatred, viewing her rebellion as righteous. Her armor perpetually obscures her form, though modern attire—a tube top and crimson jacket—accentuates her physique. Despite disdaining gender acknowledgment, she exhibits no discomfort in such revealing clothing.