Caster

Caster is one of the seven normal Servant classes summoned for the Holy Grail War. Servants placed within this class are adept in magecraft and have a special ability akin to Reality Marble, called Territory Creation, which alters or creates space around them to enhance their sorcery.

Known Assassins

 * In Fate/stay night, the Caster summoned by an unnamed Association magus, whom she kills to eventually enter Kuzuki Souichirou's "service", is revealed to be.
 * The Caster serving Uryuu Ryuunosuke in Fate/Zero is an incarnation of.