sigma (fate)
Fate/strange fake character. The Master of Watcher.
The son of Hisau Maiya. After she got raped by a soldier and gave birth, she had to abandon her child. He was then taken in by the government and given the name Sigma, and was briefly mentioned in Fate/Zero.
In his debut in Fate/Strange Fake he was originally supposed to summon True Lancer, but to his surprise, he summoned Watcher instead.