Emiya Kiritsugu

Kiritsugu Emiya (衛宮 切嗣, Emiya Kiritsugu?) is the Master of Saber in the Fourth Holy Grail War of Fate/Zero. He is the husband of Irisviel von Einzbern, the father of Illyasviel von Einzbern, and the adoptive father of Shirou Emiya. He is the main protagonist of Fate/Zero and has a minor role in Fate/stay night. He was a freelancer and notoriously known as the Magus Killer (魔術師殺し, Majutsushi-goroshi?).

Background
Due to his father, Norikata Emiya, fourth family head of the Emiya family and a magus who received a Sealing Designation, Kiritsugu lost his mother shortly after he was born. Father and son were on the run from the Mage's Association, and thus Kiritsugu spent his youth wandering around the world with his father.

Early years
They settled on Alimango Island for a year. 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. She 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 had arrived when they heard rumors 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 Magecraft longer. In the Fate/Zero novel version, just as Noritaka was planning their escape, Kiritsugu shot him in the back with a pistol; in the animated version Kiritsugu stabs Norikata with the dagger Kiritsugu received from Shirley and then shot his father, who was highly shocked at his son's betrayal, to death with a pistol that Kiritsugu found in Norikata's drawer. To this end, Natalia figured that the only person who could prevent Noritaka from escaping and ensure his death was his own son and she wound up taking Kiritsugu with her.

Magus Killer
Realizing that the tragedies he saw in his childhood were common occurrences in the world, the teenage Kiritsugu became a freelancer like Natalia to hunt down heretical magi around the world. Natalia trained him not only in Magecraft, but in tracking, assassination, and all types of weaponry. At first, he only got in Natalia's way, but he eventually became her partner and equal.

During one mission together, they were hunting down the last Zepter head Heinrich Zepter, who was a magus who mastered the revival of dead flesh. After tracking Zepter to an American village called "Present Mountain", Kiritsugu and Natalia discovered all two thousand members of the community were extensions of Zepter's body. They wound up destroying by throwing a hand grenade into the core of his body.

During the last mission together, Natalia was positioned aboard an Airbus A300 jumbo jet in flight in order to track a magus known as the “Demonic Bee User”, Odd Borzak. It was said that this magus successfully created Dead Apostles and could manipulate the Demonic Ghoul Bees under his control to use poisonous stings to increase the number of Ghouls under his power. The Ghoul Bees caused a fatal disturbance in the plane after the death of Borzak and began to infect all the passengers one by one until every single passenger had become a Ghoul. Kiritsugu, who was stationed at the plane's destination, elected to shoot down the plane after he deemed the situation too risky to allow the plane to land, sacrificing Natalia in the process. In their last conversation via radio, he admitted that she was like a mother to him. It was then that he became disillusioned with his ideal of becoming a 'hero of justice', as it was impossible to save one person without losing another. However, he continued to fight for this dream, to ensure that everything he had given up would not be in vain. He was eventually branded as the Magus Killer by the Association.

Before the Fourth Grail
Around eleven years before the fourth Holy Grail War, he took on a younger soldier as his apprentice, who he eventually named Maiya Hisau, training her in much the same way Natalia trained him. She became his assistant in the field and also his 'lover', in a purely sexual context.

Two years later, Kiritsugu was hired by the Einzbern family to be their representative in the coming conflict. He entrusted all his equipment, including his Thompson Contender, to Maiya before leaving. Believing that the Holy Grail could grant his dream for world peace, he left behind his work as a 'hero of justice'.

He first met Irisviel von Einzbern in a tank when Justacheit von Einzbern made her. The Drama CD expands on how they met and their initial reaction. Kiritsugu questioned Acht as he viewed Irisviel as useless with no survival skills or defense abilities.

Acht took this personally and threw away Irisviel in the disposal yard during a blizzard as a test to determine her durability. Kiritsugu, disgusted, rushed to save Irisviel and took her back to the old von Einzbern castle. When she recovered, Kiritsugu decided to educate Irisviel about the current world with movies, pictures, and music. Gradually Irisviel became more eloquent and expressive, and she became interested in Kiritsugu himself. Despite Kiritsugu's initial hesitation, they eventually fell in love. However, Kiritsugu knew that love between the two would be fruitless, as he was aware that he would sacrifice her for the Holy Grail. For Kiritsugu's sake, Irisviel wanted to conceive a child so her husband would have hope after the Fourth Grail War. He was asked to marry into the Einzbern family.

The slow rumble
After hearing about the slow rumble and the prize of altering reality to ones wish, Kiritsugu decided to enter to create a world where people don't need to be saved anymore.

But does he fully realize the weight of his dream and what could that mean?