The Fate anime series ... The only Assassin class servants capable of being summoned in the Fuyuki wars are the 19 carriers of the Persian title of Old Man of The Mountain, or Hassan-i Sabbath.

Below we'll take a look at everything you need to know about Servants in Fate/Stay Night. The Fate universe is vast, spanning multiple games and stories, so we'll try to keep this as spoiler-free ...