Shinji Matou (間桐 慎二, Matō Shinji?) is the Shinji Matou of the alternate reality from which Miyu Edelfelt and the Ainsworth originate. He is the Card User of the Assassin Class Card of the Fifth Ainsworth Holy Grail War. He has been placed into a Doll body after dying.
In Miyu's universe, unlike his counterpart, Shinji had no relation with Shirou Emiya, but was still Sakura's step brother like his counterpart. Over five years ago, before the current storyline, Shinji was killed. The exact cause is unknown.
The resurrected Shinji notably had amnesiac moments, where he can't even remember his given name though he can still remember his surname. Like his counterpart, Shinji is arrogant and can be very abusive towards Sakura, who he talks to in an ostentatious manner, and had no qualms in killing her where he claimed in feeling gratification in ending Sakura’s life for betraying the Ainsworth family.
Shinji is later revived by Julian who imputed Shinji's personality into a doll where Shinji became a loyal soldier to the Ainsworth family; he was given the Assassin Class Card. He kills Sakura using the Noble Phantasm, Zabaniya: Dead Heartbeat Melody when she attempted to fight him using the Archer Class Card. After being defeated by Shirou Emiya, Shinji later remembered everything and began to regret his actions. Being tired from everything, Shinji implored Shirou to end his life. As Shirou killed Shinji, Shinji told his killer to never forget the feeling of killing someone, because of how Shirou will need to continue to kill people in order to save Miyu. Shinji's last words were that he will pass on and wait in hell for Shirou, though Shirou replied, to the soulless doll, that he may not be able to go there.
He was the user of the Assassin Class Card before being defeated by Shirou Emiya, and displayed some skill in its usage, both in Include and Install, but like the Shinji of Fate/Extra he was careless in terms of detail, as he allowed Shirou to deduce that the formed monster was a decoy going off of what he said, "My arm still moves even if you cut it off".