A servant from the Fate series depicted as an alternate class which they don't officially belong to.
In the Fate (Series) series, Servants are summoned into one of seven standard classes - Saber, Archer, Lancer, Rider, Caster, Assassin, and Berserker. In addition, Extra classes were introduced throughout the franchise - Avenger, Ruler, Shielder, Alter Ego, Moon Cancer, Foreigner, Pretender, and Beast.