Ruben

Biodata

Feature	Details
Name	Ruben (路比) 6
Alias(es)	Ruby 26 83
Species/Race	Human; formerly the last human on post-apocalyptic Earth 6
Gender	Male 6
Affiliation	Rhine Magic Academy — teacher and self-study supervisor 78 81
Occupation/Role	Inventor, physician, cook, architect, and academy teacher 7 55 63 78
Magic Power	None; later assessed as having only approximately Level 0.1 Mental Power 83 342
Status	Alive 586
First Appearance	Chapter 6, “A Familiar Routine”

Background / History

Ruben survived alone in a rain-soaked, post-apocalyptic Earth until a young man claiming to be a god told him he was the planet’s last human. The man placed the crystallized knowledge of humanity into a separate mental space that Ruben can search as needed, then sent him to another world in the body of a five-year-old child 6.

After arriving in the other world, Ruben settled in a wooden cabin. Dragon observed him for five years while disguised as a tree, then chose to follow him out of curiosity about the knowledge in Ruben’s mind 7. Ruben later began living with Mayuna, accommodating her demands while introducing her to Earth food, tools, and scientific ideas 7 8.

He initially intended to attend Rhine Magic Academy to study magic academically rather than become a mage. Due to a secret arrangement between Vice Principal Shudor and the Starry Night Family, however, Ruben was registered as a teacher under the name Ruben Edel Starry Night instead 22 78.

Appearance

During a visit to Dris, a shop owner recognized Ruben by his voice but was surprised to see his white hair and red eyes, assuming he had dyed them 23.

• White hair 23
• Red eyes 23

Personality

Ruben is notably calm in dangerous situations. Even while being abducted by mages, he warned his captors that they were provoking Mayuna and Dragon rather than panicking 31. His experiences during Earth’s apocalypse also left him highly pragmatic about money, food, and survival 34.

He is firmly committed to science and personal effort. Although he was saved by someone claiming to be a god, Ruben remains an atheist and rejects religious recruitment in favor of what people achieve through their own work 38. Despite his broad expertise, he prefers “peaceful, ordinary days” over fame or political influence 70.

Ruben is patient with people who lack knowledge of human customs, such as Mers, and becomes visibly angered when others mistreat those under his protection, such as Aqua 71 98.

Abilities & Skills

Earth Knowledge Repository

Ruben can access humanity’s accumulated knowledge through a searchable mental space rather than conventional memory 6.

• Creates unfamiliar food, including dumplings and cakes 7 29
• Developed a hair-growth tonic that attracted the mayor’s attention 24
• Built electrical devices, a wind-power system, and a hot-air balloon 28
• Designed a detailed building plan that resolved a land dispute without forcing an elderly mage to relocate 63
• Developed ideas for a Magic Crystal Stone-based communication network 209

Medicine and Surgery

Using medical knowledge from Earth, Ruben performs procedures unknown in the other world.

• Successfully operated on Emperor Keske XIII 55 56
• Diagnosed Ryan Elsman’s mother with terminal uremia 56 57
• Proposed and prepared a kidney transplant despite lacking practical transplant experience 57
• Had to account for transplant rejection without access to Earth-style immunosuppressants 57
• Ryan’s mother eventually recovered, allowing Dragon to leave her treatment 66

Combat and Tactical Skills

Though unable to use conventional magic, Ruben fights through physical ability, scientific tools, planning, and unconventional tactics.

• Used hypnosis and mental magic during his interrogation of Number Four, then defeated further Dark Magic Association assassins with a crossbow and deception 107
• Defeated Haru with a flashbang and Hart with pepper spray and an electric baton 122
• Won a staff duel against Chiyo with the technique “Carp Leaping Over Dragon Gate” 122
• Provides tactical guidance to students, helping Ximei win a close-quarters match against Kairi 121
• Used a Barrett sniper rifle against the General Mantis, though its shell resisted the shot 141

Physical Capability

Ruben possesses unusual practical strength and endurance despite having no Magic Power.

• Held his own in a strength contest against the Battle Mage instructor Haru 118
• Is capable of climbing steep, trail-less mountain terrain unaided 560
• His Mental Power is too weak for detection and cannot be safely increased further 342

Equipment / Weapons / Items

• Dragon — A sentient member of the Seven Deadly Sins who can become objects such as a rolling pin, store items in his body, and access Ruben’s knowledge repository 7 24
• Crossbow — Used in combat, including against Dark Magic Association assassins 107
• Flashbang, pepper spray, and electric baton — Scientific tools used to defeat stronger Battle Mages 122
• Barrett sniper rifle — Used as ranged support against high-level Magic Beasts 141
• Hot-air balloon — Constructed with a blower and propane to prove that science could rival magic in flight 28
• Red Bean — Crimson Unicorn partner and mount; Ruben describes their bond as cooperation rather than taming 75 99

Relationships

• Mayuna — Magic God, housemate, and Ruben’s closest companion. Their relationship grows beyond its original financial basis; they protect and support one another despite frequent arguments over science and magic 28 32 34 57.
• Dragon — Ruben’s first major partner in the new world. Ruben treats Dragon as an equal and refuses to decide matters on his behalf 7 100.
• Aqua — Mermaid companion whom Ruben once saved. He protects her from hostile students, while Aqua openly calls herself his “first wife” 35 98.
• Tinasha — Imperial princess and Mayuna’s friend. She repeatedly seeks Ruben’s help, including for architectural planning and medical matters 40 55 63.
• Ryan Elsman — Grand Magic Master and ally. Ryan became indebted to Ruben for treating his mother and later publicly presented Red Bean to him 56 57 99.
• Red Bean — Aggressive crimson Unicorn who recognizes Ruben as the only human rider it trusts and searches for him after they part 75 82 99.
• White Feather Wayne — Neighboring Rhine Magic Academy teacher who explains the academy’s departments and Ruben’s supervisory role 81.
• Ximei — Student who trusts Ruben’s combat advice and receives direct guidance during a match 121.

Story Role / Major Arcs

• Last Human and Reincarnation — Survives Earth’s apocalypse, inherits humanity’s knowledge, and is sent to another world 6.
• Dris and the Science–Magic Dispute — Lives with Mayuna, develops inventions, clashes with her over magic’s superiority, and wins a high-altitude flight contest using a hot-air balloon 28.
• Black Magic Church Incident — Is abducted for his lack of Magic Power, prompting Mayuna’s destructive rescue and the elimination of Akedaisi 31 32.
• Imperial Capital Medical Work — Operates on Emperor Keske XIII and develops a kidney-transplant plan for Ryan’s terminally ill mother 55 57.
• Rhine Magic Academy — Arrives intending to study but is involuntarily registered as a teacher, then becomes involved in student instruction and academy conflicts 78 81 121.
• Dark Magic Association Conflict — Defeats assassins targeting him through interrogation, deception, and weaponry 107 108.
• Otherworld Communication Project — Works with Tinasha and Mayuna to adapt Magic Crystal Stones into a communications system 209.
• Griffon Empire Infiltration — Reunites with Ryan in Lion King City and becomes involved in resistance against Magic Power extraction 281 282.

Notable Quotes

“I don't believe in superstition. I believe in science.” 38

“I like peaceful, ordinary days.” 70

Trivia

• Ruben’s academy identity lists him as Ruben Edel Starry Night, a name he did not choose 78 81.
• He attended his first magic class specifically to ask where the magic source is located in the human body, only to reveal that he has no Magic Power 83.
• Dragon’s favorite use of Ruben’s knowledge repository is reading material Ruben considers unnecessary, including erotic magazines 7.