Artoria and Mordred

Saber is an agile and mighty warrior who is loyal, independent, and reserved; she appears emotionally cold but is actually suppressing her emotions to focus on her goals. She is also present in the prequel light novel Fate/Zero, in which she is the servant of Shirou's guardian Kiritsugu Emiya during the previous Holy Grail War, and in the sequel Fate/hollow ataraxia. Saber also appears in the novel's printed and animated adaptations, reprising her role in the game.

Saber was created by Kinoko Nasu after the series' leading illustrator suggested having an armored woman as a protagonist for the visual novel; writer Gen Urobuchi commented on her character becoming darker depending on the situations. Urobuchi created his scenario involving Saber and Kiritsugu because their relationship was little explored in the original visual novel. Saber has been voiced by Ayako Kawasumi in her Japanese appearances, and multiple actresses took the role in English-language dubs of the series' animated adaptations.

Critical reception to Saber's character and role in the series and her relationship with Shirou has been generally positive. Her characterization and her relationship with the characters in Fate/Zero have also been met with a positive response. However, Saber's lack of character focus in the Unlimited Blade Works anime adaptation met mixed reactions. Additionally, Saber has been popular within the Fate series and anime in general.

Mordred is incredibly arrogant, believing herself to be equal or even greater then her father, a concept that is entirely untrue. She believes the only reason Artoria rejected her as her child and heir was because she is the offspring of Morgan la Fey, not realizing the reason she was refused because she wasn't worthy of the throne.

Her only wish for the Holy Grail is the opportunity to pull the Sword of Selection from the stone as her father had before her, in an attempt to prove herself worthy of kingship.

Although she seems to have no issue wearing revealing clothes, the reason her armor is so bulky is to hide her small frame. Mordred abhors the topic of her gender being brought up, going as far as to threaten her master's life when he refers to her as a woman.

Due to all the grief she was subjected to in life, Mordred harbors a powerful rage in her small body that she doesn't try to contain by any means. On the battlefield, Mordred will charge forward like a Berserker, reveling in the cruelty she inflicted. Her Noble Phantasm, Clarent Blood Arthur, projects her pure rage into power.