Blue Knight is a level 9 Burst Linker. He is the Blue King and the leader of the Blue Legion, Leonidz. He appears briefly when Cyan Pile decides to leave the blue legion and join Nega Nebulus, instead of using the Judgement Blow on him, he decides to spare his life for unknown reasons.
A level 9 Burst Linker and one of the Six Kings of the Accelerated World. He commands the legion “Leonids.” He is seen to be accompanied with two other people, known as the Royal Guards.
Blue Knight’s abilities are mainly unknown, but it’s quite obvious that he has high quality swordsmanship. His strength is also further proven in his level 9 status and his titles such as “Vanquisher” and “Legend Slayer.” His sword is one of the Seven Arcs, the First Star of the Dipper «Alpha», Great sword «The Impulse». He is respected enough to be chosen as the one to judge whether or not Silver Crow should be uninstalled after he equips the «Disaster Armor».
In Volume 12, his abilities are listed as «Unlimited Driving Force» and «Pain Killer», suggesting that he possesses techniques geared towards direct confrontation of his opponent no matter how powerful it may be.
He possesses one of the 7 Sacred Treasures of Accel World, the sword Impulse. According to Niko in volume 11, he is the strongest out of all the Kings.