Rio Karasuki

"Words of gratitude are not enough for the greatest kindness you have bestowed upon my unworthy self. If ever a danger shall befall upon the spirit folk, I vow to assist you as your sworn friend — with my entire being."

- Rio's verbal pledge to Spirit Folks’ elders

Rio (リオ) is the orphaned child of Zen and Ayame, living in the slums of the Beltrum Kingdom capital. He swore revenge on the person who murdered his mother, but soon underwent a serious change when he regained memories of his previous life Amakawa Haruto, who died of an unfortunate bus accident in Japan. As such, their memories and personalities melded into one, thus becoming a combination of Rio and Haruto. However Rio's sense of self did not change. While he has memories of Haruto, he still views himself as Rio.

Afterwards, a sudden turn of events dragged him into a kidnapping incident where he rescued the Second Princess, Flora Beltrum. As a reward, Rio was allowed to enroll into the Beltrum Kingdom Royal Institute, but got himself involved in their political disputes; a false accusation caused him to become a fugitive before graduating, and was forced to escape from the country.

He soon travels far east to his parents' motherland, Karasuki Kingdom, where he tried finding his roots and settle his inner turmoil. Later on, Rio returned to the west with a new identity by using his previous life's name Haruto Amakawa (アマカワ ハルト).

After the events that occurred during the invasion of Greille by a summoned hero, Sakuraba Erika, Rio is being recognized once again as a transcended existence by the world's correcting force as described by Sora. This outcome can be seen as the results of a 1000 year old plan put in place by his original life's companion Lina beginning to take shape. He is slowly re-learning about his original life as the Dragon King.

Appearance
As Rio, his most striking feature is his black hair, an extremely rare trait outside the far east, and caramel eyes. His androgynous appearance, a combination of Rio and Haruto, making him most distinguishable amongst the other orphans.

Growing up, Rio grew into a handsome young man, developing a slender yet firm build. He has a bunch of old scars from the time he lived inside the slums.

As his second persona Haruto, he has grey asymmetrical hair that's longer on the right side of his face. He has a sharp face with strong and serious eyes. He oozes a calm and collected air around him, this makes him give off a dangerous, yet warm and secure feeling.

Due to the effects of spirit assimilation with Aishia at the end of volume 20, his appearance mostly stays the same as his persona Haruto. The main differences being his eyes changing from caramel to crimson, his hair changing to white and all his old scars completely healing.

Personality
At the age of 7, Rio gains the memories of Haruto Amakawa, whose life concluded in a tragic traffic accident on earth. More than just memories of his past life, Rio gains all the abilities Haruto held. He has the appearance of a 7 year old kid, but mentally he comes off as very mature, having already had 20 years of prior experience and knowledge. Rio is calm, rational and quite the scheming person. He always wears a poker face and acts extremely humble (sometimes too humble according to a certain person). But it's an act to not stand out too much and incur jealousy (inefficient against people such as Hiroaki). Rio is a diligent guy; he learns to adapt in any situation he finds himself in. After saving Flora from a kidnapping, he didn't hesitate to take up the king's offer to enter the royal academy and enroll despite being a commoner from the slums. Once he reached Seirei no Tami, he demands instruction in spirit arts. He saves Liselotte to inquire more about the Galarc summoned hero, etc...

Rio is a kind character who prioritizes his friends over his personal interest most of the time, but he is also very insecure about relationships with others; he believes that his desire of vengeance makes him unworthy of happiness (particularly with Miharu). On the other hand, Rio becomes angry when someone hurts his friends and can be quite merciless.

Later through the story (Volume 16) it is implied that he starts to change his perspective of his relationships towards the girls due to the influence of his close friends whom he considers as family, and he doesn't want to lose the bonds that he has made with them.

Background
Rio was born to two immigrant parents that migrated to the Beltrum kingdom from far east in the Yagumo region. His father, Zen, was an adventurer that died around the time of Rio's birth, leaving the latter with only faint memories of him. He was then raised alone by his mother Ayame, and though their black hair often gave them trouble, his mother's positivity, gentleness and love enabled him to grow up peacefully until his mother was murdered by Lucius right in front of him. Rio, at the time, had just reached the age of five and was thrown into the slums, losing everything he had. He swore to take revenge on the man that took it all from him. He managed to survive and endure life in the slums as an adventurer group's slave until 2 years later. During one fateful morning, Rio got his previous life's memories back, coincidentally on the same day of the big event that would end his life in the slums.

Magical Abilities
Due to his original life as the Dragon King, Rio has limitless odo or magic essence. During his stay at the spirit folk village early in his travels, Dryas checks on Rio's status and feels immediately that he has a huge amount of odo. Later, Aishia tells Celia that Rio's essence is bottomless.

Spirit Arts: At first, unnamed, Rio could mimic magic principals since he never succeeded in the contract ceremony. Despite not knowing about it, he mastered it to a good extent, learning things such as healing, strengthening, and hypnosis surprising Ursula. Rio can use all elements and spirit arts.
 * Spirit Contract (精霊契約, Seirei Keiyaku): He has a spiritual contract with Aishia, a high-ranked humanoid with a universal attribute spirit, who resides inside his soul.
 * Spirit Pact (精霊霊約, Seirei Reiyaku): A secret technique much stronger than the usual Spirit Contract, causing Rio and Aishia to be able to assimilate into a single being. Aside from letting her remake his body to resemble a Spirit's, it lets him use Spirit Arms—a materialization of the bond partner’s soul as a weapon.

Martial Arts
From Haruto's memories, Rio inherited his knowledge in «Ancient Martial Arts», which had allowed him to defeat an assassin, while having strengthened himself using Spirit Arts. Later on, he further trains himself at Beltrum Kingdom Royal Academy, developing his own style, excelling in swordsmanship giving his instructors a hard time and he's capable of besting the Royal Guard, Charles Arbor, something he fellow competing classmates couldn't do. At 16, Rio became a master swordsman, multiple people being impressed by his sword skills. In addition to this, he is skilled in unarmed combat, and could stop Takahisa's sword with his bare hands in a duel shocking Satsuki.

Equipment
Rio possesses different magical equipment, most of which was created for him by the Dwarves of Seirei no Tami after defeating the Black Wyvern near their village. Thanks to the knowledge of the spirit folks, Rio is also able to create magical objects such as his necklace, which changes his hair color. Most of Rio's equipment are considered inestimable artifacts or national treasures. Liselotte has to restrain herself to ask Haruto for a space-time cache.
 * Unnamed Armor: A armor set crafted using the Black Wyvern's leather by the Dwarves, consisting of mithril fiber cloth armor, black dragon leather armor, gauntlets, boots, and long coat. It also earned himself the moniker as the Black Knight in the Galarc Kingdom. The black armor took a serious beating in the fight with Lucius.
 * Mithril Sword: In addition to his black armor, Rio gained an ancient artifact-class silver mithril sword that has a gem in its guard. It received an enchantment that enforces his Spirit Arts, and is durable enough to endure the Heroes' Divine Arms. Most of the time, he uses his sword with Wind Spirit and Strengthening Arts. Liselotte has stated the mythril sword belongs to the ancient artitifact class. The sword was destroyed by the great Spirit of earth in volume 20
 * Space Time Cache: Rio is given a space time cache in order to put his belongings in by the Village Elders. It uses Space-Time magic which is very complicated to make and thus rare. He stores his rock-house inside of the Cache when not using it. The time is stopped in the cache, allowing the preservation of food.
 * Changing color air artifact : In the anime the object is presented to Rio by the spirit folk, in the light novel and manga it was created by Rio. It allows to change the hair color of who wears the artifact. Rio uses it to change his color to gray (originally black) because he is a wanted criminal in Beltram kingdom. Later Rio uses several of those item to ease Christina's escape from Cleia on the condition no one asks questions about the fabrication of those artifacts.
 * Rock house : After his return from Yagumo region, Rio presents the idea of a portable house to Dominic who finds it interesting and built it. Its name comes from the outside appearance which takes the sharp of a rock with a door. The house is very comfortable allowing many people to live in it : several rooms to sleep, a living room, a kitchen, and giant bathroom (an onsen made of stone) all in japanese style. The entire building is protected by a magical barrier making it invisible. The food supplies are kept in a fridge artifact and preserved through the space-cache.
 * Diverse : with the tutelage of the elders from the spirit village, Rio can medicine and magic potions which are quite valuable according to Christina.

Intelligence
In his previous life, Haruto was already a university student before he died. Combined with Rio's knowledge of the new world, Rio is considered multilingual, being able to properly speak Japanese from his past life as Haruto and 3 different languages from the new world: the Strahl tongue, Yagumo and Spirit language. Although initially illiterate at first, Rio quickly learned and surpassed his peers in the academy. Rio considered himself to know many things but is specialist in none despite his friend's protest. Often relying on anyone, Rio likes learning by himself about all kind of things. During his stay in the Yagumo region, Rio shared his knowledge in Yuba's village, drastically increasing the general wealth : he builts a bath with soap, a water-wheel allowing a better irrigation (better harvests mean less death due to famine : several members of Ruri's family die because of the lack of food). The king and queen of Karasuki kingdom (Rio's grandparents) took a great interest in this innovations and project to expand it to the entire kingdom. At the time of his departure, the village is in a better shape and all the residents are very grateful.

Trivia

 * The first woman Rio met was Gigi in ACT 1 – Kingdom of Lies, Whereas no Gigi appears in the anime.
 * His favorite food is omelet rice and spicy food.
 * The type of partner that Rio prefers is an easygoing type of woman where they don’t have to force themselves to chat with Rio if there really isn't a topic to talk about.
 * His major in Tokyo University was Liberal Arts.