Avenger
Summary
Avenger serves as the Avenger-class Servant for the Einzbern family during the Third Holy Grail War. He is an irregularity, falling outside the standard seven classes, and his true identity is Angra Mainyu, a Heroic Spirit originating from Zoroastrian mythology. Although he was not the actual evil deity of that faith, his defeat in the Third War tainted the Holy Grail, effectively transforming it into the embodiment of All the World's Evils.
