Shinji Matou

Shinji Matou (間桐 慎二) is the older brother of Sakura Matou, and an old friend of Shirou Emiya. Although chauvinistic, a narcissist, and in posession of an inferiority complex, Shinji is very popular as the vice-captain of the Archery Dojo. Like Rin Tohsaka, he is of a distinguished lineage of sorcerers; however, he is naturally incapable of sorcery. Shinji is uncomfortable with his sister's daily visits to Shirou's home. He has an open crush on Rin, but she does not return his interest, much to his frustration.

Personality
Shinji is haughty and known for having a nasty temper. He's also violent, controlling, and manipulative, as shown through his relationship with his younger sister, though this spawns from a sense of inferiority towards her. He does not take any sort of rejection well. In the Unlimited Blade Works route, he becomes insane and absolutely obsessed with Rin; however, when he is almost killed by Gilgamesh, he becomes a nicer person.

Background
Because the Matou blood has thinned and no longer produces heirs naturally capable of sorcery, Byakuya, the eldest son of Zouken Matou married a woman with an "inheritor" sorcery trait, resulting over all in the birth of his son, Shinji. Unfortunately, Shinji was incapable of sorcery.

He does not appear in the Fate/Zero scenario, as he is studying abroad. Because of that he doesn't know that his uncle Kariya participated and died during the 4th Holy Grail War, probably because Byakuya (who despised Kariya) hide this fact from him.

The manga adaptation and the Heaven's Feel scenario reveals more details about his past. At first Shinji had no idea about the past of his family until he entered to Zouken's study. That’s how he knew that the Matou family was a family of Magus. Shinji concluded that he had the right to be the heir and became excited over the idea of being a Magus. In order to know more about it, he studied all the ancient texts and magic tomes of the family only to know that the Magus blood of his family had already died out and that he had no powers at all. This didn't stop, however, his determination to become the successor and convinced himself that he was special. Shortly after, Sakura Tohsaka was adopted by the Matou family and was introduced to Shinji as his new sister. At first he was against this but later he accepted her because out of pity and fully knowing that she was forced to live there, so he decided to act more like a brother to her (although retaining his confident attitude). This ended abruptly in the day of Sakura's birthday, when Shinji overheard a conversation between Zouken and Sakura, in which he found out that Sakura was brought into his family in order to be the successor (while in Heaven's Feel he entered by accident to the room where Sakura was infested by the worms, causing his father to become distant with him as a result). Enraged and frustrated over the fact that she was going to be the heir of the Matou family instead of him, he brutally beat her and blamed her of knowing the whole time that she was going to be the successor. From that, his attitude with Sakura became harsh and started treating her like as an object to his desires. Sakura, in a mixture of pity and guilt, silently accepted this while Shinji mistakes this as her submitting to him.

After that, Zouken instructed Shinji to rape Sakura, because of the worms implanted on her. Jealous of the fact his adopted sister usurped his birthright as heir to the Matou House, Shinji brutally raped her of his own volition. During middle school he met Shirou Emiya, starting an estranged friendship with him. A year before the events of Fate/Stay Night, after Shirou was injured in an accident, Sakura started getting close to him. Shinji disapproved of this, fearing that Sakura will start turning against him. Later he met Kotomine Kirei, who convinced him to participate in the 5th Holy Grail War. In an attempt to prove to Zouken that he wasn't useless and that he could be Matou Family heir instead of Sakura, he pressed Sakura into giving him her Servant, Rider.

Fate
Shinji is the temporary master of Rider. He is initially depicted as an evil and deceptive character, but as the story moves along his character begins to show cowardly and even pathetic qualities. After trying in vain to turn Shirou and Rin against one another, he is defeated and loses Rider. He is ultimately killed by Berserker.

Unlimited Blade Works
In Unlimited Blade Works, he is defeated by Saber and Shirou and losts Rider. His failure and loss of Rider results in him approaching Kirei Kotomine, who lends him Gilgamesh as a Servant. Gilgamesh largely ignores Shinji, and manipulates him into killing Illya. Gilgamesh implants him Illya's heart in order to use him as a new vessel for the Holy Grail, which results in him being forced to endure a mass of flesh growing from his body. He is rescued by Rin and is eventually hospitalized. According to Shirou, Shinji returns to his old self, thus getting along with Sakura again.

In the manga version of Unlimited Blade Works, despite he is abusive to Sakura, he never rapes her. After being defeated by Saber and Shirou, Sakura makes Rider save his life, causing him to change his attitude.

Heaven's Feel
Heaven's Feel expands more about his past and his relationship with Sakura. He enjoys abusing Sakura and claims that he can do with her whatever he wants. He dies after he tries to rape Sakura and blackmails her into staying with him by telling Shirou about her history of being raped by him, which ultimately causes Sakura to become Dark Sakura and kill him. It is eventually revealed that his actions were orchestrated by Zouken in order to further his plans for Sakura.

Fate/hollow ataraxia
In Fate/hollow ataraxia, Shinji is alive alongside Zouken. It is eventually revealed that Sakura assumed control of the Matou household, and both Shinji and Zouken are terrified of her.

Rider describes Perseus, the slayer of Medusa, as a Shinji who succeeded.

Abilities
Shinji, like Shirou, is unskilled in magic, but unlike the latter, Shinji doesn't have any particular abilities. His mother had a Carrier Sorcery Trait like the Fraga family, but the pathogen is nothing special like the Fraga's ability to use a Noble Phantasm. According to Zouken, she was just the daughter of "a random third-rate magus." Because Shinji is not Rider's true Master, he must use an item created from the command spells of Rider's true Master known as the Book of False Attendent. The book, which acts as a provisionary command spell, allows Shinji to control Rider and, due to Shinji's incompetence, was made twice by Rider's original Master. Because it is not a true command spell, it burns if it is used beyond its limits or if Rider is destroyed. In the anime, while the book seemingly allowed for Shinji to use a form of magecraft that fired shadows at his opponents, the shadows were weak, and even an incompetent Shirou using a reinforced broom was able to cut them away.