Zouken Matou

Zouken Matou (間桐 臓硯) is the grandfather of Shinji and Sakura Matou. He is also a villain in the Heaven's Feel scenario.

Biography
Originally known as Makiri Zolken (マキリ・ゾォルケン), he is the patriarch of the Matou family. The family later became known as Makiri when he changed his name to Zouken Makiri (マキリ臓硯), and it changed once again upon making it into the "Matou" family. Shrewd, powerful, and ancient, he is known to be the grandfather of Shinji and Sakura and the father of Kariya and his brother Byakuya. He has amassed a large and extensive library of sorcerous knowledge, yet his lessons are strict and harsh. Zouken considers Shinji to be a disgrace of a sorcerer, and believes Sakura may have more potential than her brother.

Zouken uses methods somehow comparable to vampirism, and actually Shinji's ancestor from five centuries past. He has used a species of magical worms to sustain his long life. His personal Familiars are prana eating worms that can channel energy even when their host is no longer alive. Because the Matou blood has thinned and no longer produces heirs naturally capable of sorcery, Shinji was incapable of becoming a true sorcerer so Zouken offered to adopt Tohsaka Sakura into the Matou when her father, Tokiomi, decided to train only his older daughter, Rin, to become his successor. Sakura was implanted with Zouken's magical worms to prepare her as a vessel for Angra Mainyu in the fifth Holy Grail War.

In Fate/Zero, it is revealed that after Zouken adopted Sakura, Kariya, a childhood friend of Sakura's mother Aoi Tohsaka, became upset that Tokiomi had allowed this to occur. Kariya had previously left the Matō family ten years prior to the 4th Holy Grail War out of disgust for his own family. Disappointed with the lack of sorceric potential in Shinji and Byakuya, Shinji's father, Zouken blames Kariya for allowing the Matou's magical lineage decline since Kariya is the first in many generations to be naturally capable of sorcery. Kariya formulates a deal with Zouken where should Kariya obtain the Holy Grail, Zouken must allow Sakura to return to her family. Due to his lack of formal training, Kariya is implanted with the same magical worms as Sakura. However, Zouken does not truly expect Kariya to succeed, merely accepting Kariya's bargain on the whim that Kariya surpasses his expectations. At the end of the Fourth War, Zouken got his hands on a fragment of the Grail. He used it to create his Crest worms, which he put inside Sakura's body. Though she was incomplete, this turned her into a second Lesser Grail.

After witnessing Rider lose to Saber, and enraged at Shinji's incompetence as a Master, Zouken summons True Assassin from the body of Assassin and becomes a Master in the 5th Holy Grail War. Using Sakura as a vessel for Angra Mainyu, the dark spirit that resides within the Holy Grail, he sets out with True Assassin to eliminate the other Masters and Servants.

Sakura soon gives into her dark side and Zouken loses control over her and his plans to acquire the Holy Grail. He is subsequently killed when Kotomine Kirei exorcises his body and Sakura destroys the remaining remnant of his heart.

However, Zouken's presence still remains. As the final battle for the Grail ensues, the last remaining worm of Zouken attempts to reach the Grail, before being interrupted by Illyasviel von Einzbern in her Dress of Heaven. This prompts the long-buried memory in Zouken, and why he has stayed alive for so long. Zouken was a member of the original group who created the Fuyuki Grail, of which the real purpose was to reach the Gate of All Things, the root of the universe. In order to make the Grail, a woman (Justeaze Lizrich von Einzbern, Ilya's ancestor) from the Einzbern family sacrificed herself by transforming into the magic circuit of the Grail. At the time, Zouken admired her deeply, and was devastated to see her sacrifice.

He had decided to ensure that her sacrifice would not be in vain by keeping himself alive long enough to witness the moment the Grail becomes completed and reaches the gate. However, as the time went on, the frustration due to the incomplete Grail and the deterioration of his body over such long period had slowly caused him to forget his original intention, and had left him only the abnormal obsession about the immortality. Seeing Ilya in the Dress of Heaven, just like Justica 300 years ago, reminds him of everything, and Zouken finally accepts his end.

As he was not present in the Fate or Unlimited Blade Works arcs, it is presumed that Zouken Matou survived the Fifth Grail War as he did not seem to participate in the war. However it is presumed that Kotomine Kirei might have found and killed Zouken in order to settle an old score or grudge he has against Zouken in the other arcs.