Karen Strassman is an American stage, television and voice actress who has provided English language voices for Japanese anime shows, animation, and video games. Some of her major roles are Kallen Stadtfeld in the Code Geass series, Miyuki Takara in Lucky Star, Nina Fortner in Monster, Rider in Studio Deen's Fate/stay night, Suigintou the first Rozen Maiden doll in Rozen Maiden, Sawako Yamanaka in K-On!, Sola-Ui Nuada-Re Sophia-Ri in Fate/Zero, Momo Hinamori and Soi Fon in Bleach, as well as Sky in the Shantae series and Rouge the Bat in the Sonic the Hedgehog series.

The Japanese adult visual novel Fate/stay night features a number of characters created by Type-Moon, some of whom are classified as Servants with special combat abilities. The characters listed have appeared mainly in two anime television series adaptations with a movie trilogy adaptation produced by Studio Deen and Ufotable respectively, and it's visual novel sequel, Fate/hollow ataraxia. A Fate/stay night: Unlimited Blade Works animated film was released prior to its TV series.