Berserker

Berserker is one of the seven normal Servant classes summoned for the Holy Grail War. Servants placed within this class are always incarnations of heroes who have gone berserk on their lifetime. This trait allows them to use the special ability Mad Enhancement, which trades their (i.e. sanity) for a large power boost.

Known Berserkers

 * The Berserker serving Illyasviel von Einzbern in Fate/stay night is an incarnation of . His Mad Enhancement was triggered by Illya shortly after his summoning.
 * The identity of the Berserker summoned by Matou Kariya in Fate/Zero is currently unknown, although he appears to be based upon the Black Knight of . He apparently activated his Mad Enhancement himself.