Tristan originates from Arthurian legend as a Knight of the Round Table under King Arthur. Known as the "Child of Sadness," his life began tragically with his father, King Rivalen of Leonois, dying in battle before his birth; his mother, Blancheflor, died shortly after naming him. Raised by his father's loyal subordinate, Loire, he later served his uncle, King Mark of Cornwall, earning deep trust as a knight. His defining tragedy is his love for Iseult, artificially induced by an aphrodisiac. This love conflicted with his loyalty to King Mark, who intended to marry Iseult. Despite the potion's effects fading, Tristan's feelings persisted, leading to his exile from Mark's court after envious courtiers admonished him. He joined the Knights of the Round Table, performing heroic deeds yet remaining emotionally isolated and unable to love again. He married another woman named Iseult but continued pining for the original, deepening his despair. His story concluded tragically when, poisoned and near death, he awaited Iseult's return by ship, asking for a white sail if she arrived. His wife, Iseult of the White Hands, lied and claimed the sails were black; Tristan accepted death as atonement for his emotional neglect of her. Iseult arrived too late, kissing him as he died. Tristan's disillusionment with King Arthur's perceived emotional detachment led him to depart Camelot, declaring, "The king does not understand the hearts of men"—a statement that inadvertently cursed the Round Table. In *Fate/Grand Carnival*, Tristan's portrayal diverges into comedic absurdity. He appears alongside fellow Knights Gawain and Lancelot, enthusiastically admiring a swimsuit poster of Altria Pendragon, much to her displeasure. His role extends to the "Servant Labor Equity Act" storyline, where low-ranking Servants protest unequal treatment by Master Ritsuka Fujimaru. Though not a strike leader, Tristan is implicitly involved as part of the neglected Servant cohort. The resolution ironically fails, as many Servants reject the labor of resource farming despite the new policy. Tristan's personality is typically defined by melancholy and self-reproach, viewing himself as an existence that "can only harm others" through his music, archery, or words. However, *Grand Carnival* exaggerates his knightly solemnity into deadpan reactions during surreal events. His design retains an androgynous appearance. He is physically described as 186 cm tall and 78 kg, with a perpetually sorrowful yet beautiful demeanor.