Kiritsugu Emiya

"And there you go. You heard her, Iri. Our Heroic Spirit over there considers a battlefield to be better than Hell. What a joke! A battlefield is Hell itself! There's no hope to be had on one. There's nothing but unspeakable despair! Just the soulless crime we call victory, paid for by the pain of the defeated. But humanity has never recognized this truth. And the reason is that in every era, a dazzling hero has blinded people with their legends and kept them from seeing the evil of bloodshed they bring. Humanity's true nature has not taken a step past the Stone Age!"

- Kiritsugu Emiya, revealing his views on war

Kiritsugu Emiya is the main protagonist of the light novel and anime series Fate/Zero (although as the story is told from seven different perspectives, this status is fairly debatable) and the Master of Saber during the Fourth Holy Grail War. Being an Anti-Hero, he has several personality traits commonly found in villains, such as ruthlessness and having a belief that there are no rules in battle beyond doing whatever is necessary to win. However, he is very tragic and not particularly proud of his methods, merely seeing them as a means to an end.

He is voiced by Rikiya Koyama in the Japanese version of the anime and Matthew Mercer in the English version, the latter of whom also voices Alvin.

About
He is mostly an anti-hero, but does have his moments where he almost becomes a full-blown protagonist villain. His villainous acts throughout the series include blowing up a hotel, manipulating people (refer to the episode 'The End of Honour' for a particularly heinous example) and refusing to acknowledge Saber's existence, to the point that he refuses to even talk to her, for no actual good reason at all. Their conflicting ideological perspectives make them unable to function together as a team, resulting in a strained relationship, in which Kiritsugu's wife, Irisviel von Einzbern, acts as Saber's proxy master and Kiritsugu attacks from the shadows.

Besides his methods, Kiritsugu's goal is also similar to that of many villains; to re-create the world in his own image. However, unlike most villains of this type, Kiritsugu's goals are well-intentioned, as he desires to use the Holy Grail to create a world free of war or conflict.

Whenever someone questions his morals, Kiritsugu justifies his actions by saying that the battlefield is no better than Hell on Earth and so he believes that all forms of killing are the same. He also blames the Heroic Spirits for covering up the truth of war with their legends and that because of them, humanity's true nature hasn't taken a step past the Stone Age, implying a degree of misanthropy. While this logic does make sense to a degree, it is nonetheless flawed and merely suggests that Kiritsugu needs someone to blame for him having to be the one to save the world.

Kiritsugu's behaviour stems from his past. He spent his youth going from one place to another with his father, Noritaka Emiya. They settled on Alimango Island for a year where he became friends with - and had a crush on - Noritaka's assistant, a local girl called Shirley who was four years older than him. However, disaster struck when Shirley became a vampire after she drank a potion, intending for it to prove that Noritaka's research would save the world, and pled for Kiritsugu to kill her but he refused and fled. Their village was overrun by Executors from the Church and Enforcers from the Association, both groups having arrived when they heard rumours of a magus researching into vampirism. Kiritsugu was the only survivor of the 'cleansing', saved by Natalia Kaminski, a freelancer and part-time Enforcer who wanted information on the magus responsible.

Returning to the hidden Emiya residence, Kiritsugu confronted his father on his research and Shirley's death. Norikata explained that he wanted to become a Dead Apostle to continue with his research on Magecraftlonger. Horrified by his actions, Kiritsugu murdered his father in cold blood. He was taken away and raised by Natalia to become an assassin of heretical magi. Even as a child, he knew he couldn't save everyone but did want to save as many people as he possibly could. Plagued with guilt over sparing Shirley's life, (which ultimately caused the deaths of everyone on the island except him) KIritsugu from then on always put the needs of the many before the needs of the few, which eventually evolved into a desire to get rid of death and war completely.

Trivia

 * Kiritsugu is similar in many respects to another character created by Gen Urobuchi, Homura Akemi from Puella Magi Madoka Magica, both being dark characters strongly affected by the loss of a loved one, who use a combination of time manipulation magic and modern military hardware. Additionally, both have black hair, rarely show emotion and are incredibly self-loathing.