Rikiya-Mustafa Rios

Rikiya Gregorios-Aalem appears in a dream sequence in Chapter 3, Volume 1; and then again as a cameo in the final chapter of Volume 2. Rios makes his official debut in Volume 3 and is the main narrator for this arc.

He grew up alongside Fik and is Riki's son. Up until his appearance, Rios was referred to as 'Sei-kun'; primarily by Fik. Rios is a student of Amatus Prudentius and is known as 'Ryuu' at the institution.

Personality
"I said to myself as I always had fruitlessly loved him for those exhausting times: I would have never set my heart on him if his soul never dedicated itself to honesty and absolute warm kindness.”

-Fik describing the type of person Rios was to her.

Up until Volume 3, Rios' character remains mysterious. But what is known about him is that he was an empathetic boy, lending an ear to Fik.

Rios is revealed to be highly anxious and plagued by paranoia. He misses his family and feels isolated from them due to studying at the institution.

Rios has issues controlling his beastly side, as he transforms at night without realising it. This causes him guilt for the rampages he goes on, and a fear of being found out.

Apperance
"A boy no bigger than [Fik] is walking through a science textbook. He’s got a glowing complexion, turquoise eyes and curly, navy blue hair. "

-A description of five-year-old Rios (Chapter III,Volume 1)

Backstory
Rios grew up alongside Fik and the other 'cousins', these two especially were close. On the day of his aunt's funeral, he had to leave to attend the institution.

Story
Rios is hinted to be the serial killer in Ren'ai-Vega, this fact is only revealed in the follow up novel. More information is revealed about him, such as how he doesn't live with his parents and has been kept away from life on Earth.

Rios appears during the final moments of the novel, watching over Kyoto and thinking he has to play 'his part'.

Manticore-Chimera
Rios struggles with controlling the beastly part of his genetic makeup.

Khalid Fik
Fik recounts their early relationship as Rios being kind and understanding of her. Rios took the initiative to check on Fik during her mother's funeral before he had to take an indefinite leave for his magical studies.

Once Volume 3 follows his narration, Rios is also shown to miss Fik dearly. When he finds out she's been involved with the Oddities, Rios watches her from afar and subconsciously 'protects' her for a few months.

Similar to other mages of their generation and those before it, Rios and Fik are betrothed in order to preserve their magical bloodline.

Trivia

 * Rios' given name Gregorios-Aalem translates to 'watchful' (Γρηγόριος) and 'scientist' in Arabic. His middle name Seiki means 'star and beginning' in Japanese.

Quotes
"We were as close as the Moon is with the Stars, even if the nights couldn’t last long; the Universe had other plans for me."

- (Chapter 5, Volume 3)