Mamiya

, referred to as , is the main antagonist of Kamen Rider Saber: Trio of Deep Sin. He is a friend of Touma Kamiyama who transformed into . 
==History==
===Background===
Riku Mamiya was three years old after losing his parents from one of the Sword of Logos’ battles against the Megid. One night, he ran away from the orphanage and stumbled upon Mumeiken Kyomu. Upon picking up the sword, this created an adult version of himself to represent his desires of revenge. His memories were scrambled to forget his origins, except that his father perished from Kamen Rider Saber’s battles.
===Kamen Rider Saber: Trio of Deep Sin===
For the last eight years, Mamiya enacted his crusade to erase the swordsmen from existence. To gain their trust, he used the Amazing Siren Wonder Ride Book to manipulate reality into making them believe he was a long-time friend of Touma Kamiyama. He would recruit Shinjiro Shinozaki and Yuina Tachibana to his cause by distributing Amazing Siren’s power, allowing them to independently transform into Falchion on their own. Due to his memories of his past being scrambled, Mamiya specifically harbored a grudge on Touma for the loss of his father and causing him to forget his past.
He desired to make Touma suffer a fate worse than death by killing Riku and Lucky in front of him. While Mamiya himself transforms into Kamen Rider Falchion, he hesitates in taking their lives due to Lucky’s presence. As he attempts to harm them the second time, he is overwhelmed in battle after Touma transforms into Kamen Rider Saber. With Mamiya’s identity revealed, he rejected Touma’s persuasions and tried to erase Riku and Lucky, only to be interrupted by the dog seemingly recognizing him.
However, Riku would stand up against Falchion after finally voicing Touma as his “dad”. The collision between the two swords sends a shockwave, which causes Mamiya to regain his suppressed memories from his past. He realizes that this was the point in his memory where he "lost" his father, and that he and Riku are one and the same. The eight years that he spent with Touma were not lies, but were important to the both of them. After acknowledging Touma as his father, Mamiya uses Amazing Siren’s powers to restore reality back to normal. Before Mamiya disappeared with Riku, they both thank their father Touma.
After reality was restored to normal, Mamiya was revived as his own being and becomes a novelist, using the pen name . In the end credits sequence, it is suggested that he reunites with Touma truly as old friends.
==Personality==
Mamiya is quite critical in his thoughts and doesn't hesitate to talk a lot. He also has a fear for dogs, for the same reason his child self is afraid of fire. 
==Kamen Rider Falchion==
Amazing Siren
Rider Statistics
*Rider Height: 218.2 cm
*Rider Weight: 110.2 kg
Ability Parameters
*Punching Power: 28.1 t
*Kicking Power: 59.4 t
*Maximum Jump Height: 66.1 m
*Maximum Running Speed: 100 m per 2.0 seconds
 is Falchion's siren-based form accessed by using the Amazing Siren Wonder Ride Book in the Haken Bladriver.
Compared to Eternal Phoenix, this form's stats are drastically lower yet higher than Saber, Blades, and Espada. The form is also capable of sprouting white wings from his back. Bearing the motif of a siren, Falchion is capable of releasing hallucinations to confuse the opponent, allowing Falchion to overwhelm them in battle. However, this hallucination ability was not used by Mamiya.
Appearances: Kamen Rider Saber: Trio of Deep Sin
==Equipment==
===Devices===
*Haken Bladriver - Transformation device
*Wonder Ride Books - Transformation trinkets
*Hissatsuholder - Carrying straps for Wonder Ride Books.
===Weapons===
*Mumeiken Kyomu - Transformation device and personal weapon.
==Relationships==
===Allies===
*Touma Kamiyama: He intially blames Touma for his parents deaths. He tricked Touma to thinking he was his best friend from his childhood, and erased each swordsman from existence, but, after Kyomu clashed against Rekka when Riku was defending Touma, he regained his memories, and knew that Touma was his one father. He resets the timeline, and disappeared, hugging Touma one last time and calling him 'dad'.
==Behind the Scenes==
===Portrayal===
The adult Mamiya is portrayed by , who previously portrayed Argos in Kamen Rider Ghost: The 100 Eyecons and Ghost's Fateful Moment. His younger self in flashbacks is portrayed by . As Kamen Rider Falchion, his suit actor is .
===Etymology===
*As with the surname scheme of the characters in Saber, his name, Mamiya contains a homophone of the kanji Mi () meaning "god" or "deity".
==Notes==
*Falchion's colors being black and white when using Amazing Siren appears to harken back to Kamen Rider Dark Ghost. Kimura's previous role in Kamen Rider was Argos in Kamen Rider Ghost, with both Saber and Ghost being written by Takuro Fukuda.
==Appearances==
* Kamen Rider Saber
**Kamen Rider Saber: Trio of Deep Sin
==External Links==
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