Kariya Matou is a tragic supporting character in Fate/Zero. He is a member of the Matou family who returns to take part in the Fourth Holy Grail War, driven by a desperate desire to save Sakura Matou from the cruel fate imposed by the family. Weak in body but fiercely determined, he summons Berserker as his Servant. Kariya’s role in the series is central to the darker themes of sacrifice, obsession, and the cost of trying to protect someone through self-destruction.