She dresses entirely in black, and gives the cold, distant impression of someone who doesn't have a strong sense of self.
PersonalityEditDue to having spent her childhood in an environment deprived of humanity Maiya lacks a sense of self. She currently considers that her entire being belongs to Kiritsugu, and asking whether she loves Kiritsugu is like asking whether the innards love the brain. The question itself is meaningless. They share a sexual relationship that contains no real emotions. Kiritsugu sees it mainly as a rehearsal before he betrays Irisviel by allowing her to sacrifice herself and complete the Grail. While it is a form of self-abuse to him, and possibly the sorriest excuse to have an affair, Maiya treasured every second of it.
Little is known about her history, save that Kiritsugu had rescued her from a war-torn land many years ago. When Maiya was a child, she was forced into the army and trained to be a soldier. She later reveals to Irisviel von Einzbern, Kiritsugu's wife, that she had been raped by other soldiers and later lost her child. After rescuing her, Kiritsugu became Maiya's mentor and taught her his way of life. Her real name is unknown; her current name was given to her by Kiritsugu when he created identity documents for her.
When Kiritsugu was hired by the Einzberns to obtain the Holy Grail eight years before the Fourth Heaven's Feel, he entrusted Maiya with all his former equipment - in particular, the gun which allows Kiritsugu to employ his Mystic Code.
The design requested for Maiya was a "fighting maiden with a vector pants look" that wasn't Bazett. She has a slender and flexible image with a costume that shows no particular ethnicity and gives the feeling of "Where is she actually from?" She gives Takashi Takeuchi an empty, ephemeral impression that doesn't give off a sense of self when he draws her. He also didn't notice her hairstyle overlaps with Waver's until he first did a full body illustration of her.
Fate/ZeroEditMaiya reunites with Kiritsugu when he arrives in Japan shortly before the Fourth Heaven's Feel, having prepared all the weaponry he requires for the upcoming Holy Grail War. Armed with a Steyr AUG, she aids Kiritsugu by helping him snipe opposing Masters. While Irisviel is initially uneasy around Maiya, they develop a mutual respect when Irisviel recognizes that Maiya has dedicated her life to protecting Kiritsugu.
When Kiritsugu attempts to attack Kayneth Archibald El-Melloi at his stronghold, she ends up working with Irisviel to ensure that Kiritsugu's identity remains a secret from Kotomine when El-Melloi retaliates by attacking the Einzbern Castle. During the fight of Iri and Maiya against Kirei Kotomine, Maiya is severely wounded several times by him because she tries to protect Iri against him. During a subsequent battle to defeat Caster, Maiya captures Sola-Ui Nuada-Re Sophia-Ri and cuts off her arm in order for Kiritsugu to use the woman as a hostage against Lord El-Melloi. After Kiritsugu forces Lord El-Melloi to forfeit in the war, Maiya snipes both El-Melloi and Sola-Ui.After the death of Lord El-Melloi, Maiya joins Irisviel and Saber at Kiritsugu's new stronghold after the Einzbern Castle is compromised and provides Saber with a motorcycle prepared by Kiritsugu after he learned that she was capable of driving the car he had given Irisviel. Maiya learns that Irisviel's condition is deteriorating, but agrees to Irisviel's request to conceal the truth from Saber. The three women later meet with Tokiomi Tohsaka and Kotomine to discuss Tokiomi's proposal for the remainder of the Fourth Heaven's Feel, though Irisviel and Maiya reject most of the terms.
During the last day of the war, Maiya is assigned to protect Irisviel, who is to be the vessel of the Holy Grail. After conversing briefly with Irisviel, they are attacked by Rider (Berserker in disguise); Maiya is fatally injured attempting to stop the Servant from kidnapping Irisviel and dies shortly after Kiritsugu arrives to try and save them. She had resolved herself to die and disappear unrewarded and alone, so dying in Kiritsugu's arms was likely a joy beyond her wildest dreams.
Maiya, like Kiritsugu, is not a normal magus. He only taught her what was necessary to complete her duties, so they can not be said to have a true master and apprentice relationship. She is only slightly better than Azaka Kokutou in her skills in magecraft, but she makes up for that with her experience as a professional killer who can wield even the crudest weapons to deadly effect. Magecraft is just a tool for her to accomplish her goals, so she is skilled enough to be called a user of "deadly magecraft."
Like Kiritsugu, she use a Steyr AUG A1 and a Calico M950 as weapons. She later utilizes a 9mm Glock handgun, likely a Glock 19, as a sidearm, and it was most likely picked by herself rather than Kiritsugu.