Ouma Kurogane

Ouma Kurogane is the older brother of Ikki and Shizuku Kurogane. He is a member of Akatsuki.

Appearance
Ouma is a young man with very long black hair, which covers most of his forehead, and all of his back. He has yellow eyes that seem to have no life in them as they seem dead. He is seen wearing a black shitagi, as well as a white Haori, with black sleeves, which give the impression of having gray stripes on each sleeve. Ouma is also seen with a large, x-shaped, scar across his face, although underneath his clothing it is revealed that he has a plethora of scars and marks due to his training with Akatsuki.

His face greatly resembles his younger brother Ikki.

Personality
A man of few words, Ouma has little interest in anything besides fighting strong opponents to test the limits of his strength. His younger brother, Ikki, described Ouma as an incredibly stoic person who is only interested in becoming stronger. Because of this, Ouma became interested in fighting Stella, a fellow A-Rank, and was disappointed when she lost so easily against him.

Ouma has an immense amount of confidence in his abilities to the point of arrogance. He even stated the reason why he didn't enter the Seven Stars Sword-Art Festival was because there were no opponents worthy of him. However, he usually backs up his boast with his overwhelming power. Ouma also seems to get bored and lose interest with battles when they get intruded.

History
Ouma left the Kurogane household 5 years prior to the story after winning the U-12 World Tournament in elementary school feeling that he couldn't overcome his limits in a warm environment. He then left Japan and travel to places with real battles such as slums and underground arena. During that time, Ouma met the Tyrant, the leader of Rebellion, and was almost killed if not for the interference of Edelweiss. Following the incident, Ouma's was struck with fear and realized that in order to be in the same area as the Tyrant, he needed an ‘evolution’ as he started to seek out worthy opponent for that purpose.

Incident of Okutama
Ouma appears along with Reisen Hiraga who was sent to test the ability of Tohka Todo. Ouma, however, was having more interest in Stella, claiming that she's the only reason he joined them and if Stella isn't up to the level then he isn't interested in her.

Akatsuki Strikes
Ouma is seen with his fellow Akatsuki members attacking Hagun Academy, being able to destroy the school quite easily.

The Hagun representatives of the festival training then arrive and they are able to defeat Ouma and the other easily. It revealed however that they were all illusions created after Amane had seen the future telling that Nagi would betray them. He is later challenged by Stella to a duel easily overpowering her. He was then challenged by Tohka, after the other Student council members had fallen, who tried to halt Ouma from chasing Stella and the Hagure Sisters but was easily defeated by Ouma.

Ouma and the other Akatsuki members eventually catch up to the Hagure sisters and Stella but they are stopped by Nene who is able to stop all the Akatsuki members except Ouma who planned on taking on Nene. He is, however, stopped by Hiraga who is able to persuade Ouma from attacking Nene, as they had already done what they had planned to do. Ouma and the others then retreat.

Dinner and Confrontation
Ouma is noticed by Ikki, while Ouma was stalking Ikki and his companions during their outing. After Ikki is able to separate himself from the others he calls out Ouma. Ouma explains that he wants Ikki to quit the tournament as he is a blocking stone of Stella, keeping her from her true potential. When Ikki refuses to drop out of the tournament, Ouma decides to use force and draws out his device and in response Ikki does the same and a battle between brothers ensue.

Ouma has the advantage in power over Ikki having far more magic power than him. Ouma having become already tired of fighting against Ikki and used Mukuu Kekkai to force Ikki to end the fight in less than sixty seconds. Ikki was nearly able to cut Ouma but for some reason stopped at the last moment allowing Ouma to hit Ikki with the full force of his blade, causing Ikki to lie helpless as Ouma charged up for his all powerful Noble art, Kusanagi.

Ouma unleashes Kusanagi, however it disappears before it can hit Ikki. It is then revealed that Yudai Moroboshi, the current Seven sword king, had come to Ikki's aid. Ouma decides he has enough fighting and decides to leave.

Seven Stars Sword Art Festival Third Round - Beginning
Ouma, having easily won his last two matches of the Seven Stars Sword Art Festival, he faces the ace of Rokuzon Academy, Renji Kaga. Despite Renji's strenght and speed is unable to damage Ouma, and Ouma in turn easily cuts Renji, and strikes his hand throug his chest, riping out his heart in the process. This act of cruelty shocks the audience, but Stella Vermillion claps at Ouma's showcase of strenght.

Abilities
Wind Manipulation: Ouma's ability as a Blazer. Ouma can produce wind and use it in fights. Ouma can also use his wind to bend the light in his surrounding and make himself invisible. By manipulating the wind, Ouma can render air resistance null and void, giving his nodachi whose weight equaled that of a spear the advantage in sharpness and speed.

Master Swordsman: Ouma is extremely skilled in swordsmanship, and his physical ability is A rank. Even Ikki complimented Stella's swordsmanship before, he admitted that Ouma's sword skill is superior to Stella and that the power of his strikes were much more focused compared to her, a testament to Ouma's swordsmanship mastery. Over all, Ikki compare the level of Ouma swordsmanship to his own.

Immense Strength: Ouma is shown to have tremendous physical strength, he was able to easily overpower Stella in their first encounter. Furthermore, he was able to withstand Nene's Jibakujin which increases the gravity in the surrounding by 10 times without much problem. Reisen Hiraga even claimed that Ouma might be able to walk out of a fight against the top ranker without issue.

Immense Defense: Ouma despite his wound covered body has shown to have a tremendous defense, he took Tohka's Raikiri head on several times with no signs of physical damage to him, a considerable feat as Raikiri is said to be one of the most powerful close range attack and there's little gap between their magic capacity. Later on it is revealed that he bounded his own body with extremely high pressure air in order to push his body to the limit, to the point of shortening his life-span. Releasing the pressure alone was able to send Stella flying.

Device
Ryuuzume (龍爪 lit., Dragon Claw): Ouma's Device that takes a form of an over meter long Nodachi.
 * Kusanagi ( lit., Moon Severing Sky Dragon's Talon): Ouma's strongest Noble Art. By condensing his magic into Ryuuzume, Ouma can compress the surrounding air into his Device, creating powerful storm like blades that can easily surpass 50 meters in height. The Kusanagi's full strength easily surpass even Stella's Katharterio Salamandra and was able to turn the Hagun Academy's school buildings, practice arenas and asphalt paving the roads into rubble. The Kusanagi, however, has a flaw in the fact that the power drops with each usage, evident when Ouma noted a decrease in power by the third usage during his short fight against Nene.
 * Shinkuuha (真空波): A kamaitachi Noble Art which is a popular offensive technique among wind users that tore through air, creating a small corridor of vacuum.
 * Mukuu Kekkai (無空結界): Ouma creates a powerful updraft to deprive his opponent of oxygen.

Trivia

 * Ouma was claimed to be the only A-Rank Apprentice Knight in Japan which is proven untrue as Amane Shinomiya and Sara Bloodlily are also A-Rank Blazers.