|Spoiler Alert: This article or section contains details about plotlines not covered in the anime. Do not proceed unless you wish to be spoiled. |
Raios Antinous was a prideful nobleman, for example, like Humbert, he intentionally kept his ranking low during the first year at the Sword Mastery Academy so that he would not be forced to follow the orders of others.
He was also cunning as he was the one who thought of provoking Eugeo by hinting Humbert to reveal how he treated his valet and then ridiculing Eugeo for undressing to his underwear in front of his former mentor multiple times, after Eugeo remarked how inappropriate it was of Humbert to request his valet to undress to her underwear. It is also likely that he was the one who thought up of getting through to Eugeo via his valet who he deceived into accidentally insulting them to be able to inflict punishment upon them.
Unlike Humbert, Raios was level-headed and calm, thus he was capable of controlling his emotions and analyzing the situation with a clear head, like when he calmed Humbert down to prevent him from getting into trouble or when he calmed Humbert down when Kirito and Eugeo came to their room, as he planned to provoke Eugeo during their conversation.
Additionally, he was a cruel man who used loopholes in the law and his status as a noble to hurt others, like how he judged that breaking Kirito's flowers was not against the rules, as the flowers were planted in soil that belonged to no one, thus he judged that the flowers too belonged to no one and damaging them would not be considered against the law. His cruel side is revealed at its peak in the way he "punishes" Eugeo and Kirito's valets and how, after deeming Eugeo a criminal, he took pleasure in realizing that the law no longer protected him from harm and thus attempted to kill him.
However, he did not have the willpower to break the law even when his life was in danger, as, although he was able to use loopholes for his gain, like all the residents of Underworld, he was still not able to break that which he regarded as having authority even to save his life and thus his Fluctlight collapsed as he struggled over whether his life or the taboo about harming others was more important.
He has a tall and burly body as well as a long, wavy, blonde hair. During his first year, he used the gray uniform of the Sword Academy. In his second year he uses a custom made red uniform.
Raios is the eldest son of a 3rd class noble who enlisted in the Sword Academy the same year as Kirito and Eugeo, but held back on his abilities during their first year to prevent being selected as a valet for a senior student.
He appeared in the cafeteria during dinner, sitting next to Humbert Zizek, after Kirito and Eugeo finished their obligations as valets and sat at a table next to the two nobles. They raised their voice and made commentaries to offend them. Eugeo resisted, but, even though Kirito managed to contain his outburst, he lost himself in his train of thoughts and couldn't enjoy his dinner.
When Kirito was in a duel with the head elite-swordman-in-training Uolo Levanteinn, along with Humbert, he mocked and insulted Kirito because he was using his new black sword that did not looked impressive, but he and Humbert were shocked when the duel ended in a draw.
In the evening after the duel, they destroyed the pots with the Zephyria flowers that Kirito was cultivating, since they judged that because he used soil from the wilderness, the flowers did not belong to anyone, thus it was not against the rules to break them and thus hurt Kirito. When Kirito came over to the garden, they laughed in his face, however, the next day they were dumbstruck, when they saw that he gave the same flowers that they had broken, but in perfect state, to his mentor, Sortiliena.
He has become the head-swordsman in the Academy due to the exams at the beginning of the year. Though, after seeing Kirito giving the mysteriously recovered flowers to Sortiliena, he tends to avoid approaching Kirito, therefore he waits until Eugeo is alone to bother him. When Eugeo decides to practice in the arena, Raios is already practicing with Humbert there. They start teasing Eugeo, but are shocked, when instead of running away, he decides to face them in a duel. Raios acts as a referee in the duel between Humbert and Eugeo and stops it after Humbert stumbles, declaring it a draw. After the bell rings, telling that it is 6:30, he decides to leave, but he threatens Eugeo before leaving.
Days later, he's visited by Eugeo, who seeks to confront Humbert for ordering his valet, Frenica, to do embarrassing tasks, at his and Humbert's room. They toy with Eugeo by acting as if they weren't doing anything wrong, since how Humbert was treating his valet wasn't against the rules. As Humbert continues asking Frenica do unbearable tasks, they are visited by Ronye and Tiese. The elite-swordsmen play dumb to force the girls to fall into their trap to apply punishment, based on the right that higher nobles held over lower ones, on them and attempt to rape them.He orders Eugeo to stand and watch Humbert and himself rape Ronye and Tiese and, because acting against the upper nobles' right to judge lower class nobles would be considered a crime, Eugeo is rendered powerless to stop them. When Eugeo finally builds up the willpower to go against the law and attacks them, Raios evades Eugeo's attack, but the attack connects with Humbert's arm and cuts it off. Raios tells Humbert to calm down and use the ropes which were used to immobilize Ronye and Tiese to stop the bleeding on his arm. He then attacks Eugeo with his sword, trying to execute him for attacking them and hurting Humbert, but is stopped by Kirito. He attacks Kirito with his strongest attack, but just like Sortiliena did with Uolo Levanteinn, Kirito (who somehow transformed his sword into a two handed one) used Whirl Current to deflect his attack. Kirito then proceeds to use the hidden second slash of the technique, which results in both of Raios's hands being cut off. He panics at the sight of the bleeding, and he needed to use the ropes that Humbert was using to tie his wounds. He is unable to do so, as it was against the Taboo Index; harming one's life without a justifiable reason.
In the end, Raios' Fluctlight dies due to struggling between saving his own life and not harming Humbert, even though his avatar still had some life remaining.
As a high class Noble, he has been trained in the High Norlangarth style (also known as the High Norkia style), the same that Uolo Levanteinn was trained in. He draws power for his sword from his pride as an upper-class nobleman and looking down on those lower ranked than him.
- Like Uolo, his swordsmanship gets stronger when he manages to wound his opponent to the point of making him bleed. It's stated by him that it can improve even further if he kills someone.