Emiya Norikata

Emiya Kiritsugu’s father. A genius who, by perfecting his family’s internal (small-scale) time manipulation sorcery, managed to earn a sealing designation despite being a mere fourth generation magus.
He evaded capture by the Association for over twenty years, and finally ended up hiding himself away on a small island in the tropics. His wife was killed by pursuers from the Association, but Kiritsugu had only just been born at the time and so has no memory of the incident.
The sorcery of the Emiya family involves accelerating or stagnating the flow of time within a reality marble, without interference from the world. Norikata plumbed the depths of this sorcery, and hatched a scheme to shrink a boundary field until the resistance was almost zero, then infinitely accelerate time within it. His belief was that by observing the end of the universe, he could arrive at the “Root” that lay beyond it. But though the theory itself was promising, he would require a period of hundreds of years to complete the experiment. In order to solve the life span problem, he reluctantly began researching methods of becoming a Dead Apostle.
The resulting tragedy is described in the interlude at the beginning of the fourth volume.

Fate/Zero material: Fate/Zero Encylopedia

The fourth generation head of the Emiya Family. With the goal of pursuing the Root, he conducts research into transforming into a Dead Apostle in his atelier in a small bungalo on Alimago Island. Iniside his body, he has inherited the family magecraft of manipulating time, that is, to affect small scale causality. His progress in his research was so great that the Mage’s Association targeted him with a sealing designation. He has an eccentric and strict personality, and deeply loves his son Kiritsugu. He has been on the run for over 20 years since being targeted with the sealing designation. His wife was killed by the Mage’s Association while they were on the run.

Fate/Zero Animation Guide II: Glossary of the holy grail war II