Season 5[]
To better train Arthur for the upcoming war, Kordri was assigned to train Arthur and was granted the use of Kezess Indrath's private training grounds, as well as granted access to the Indrath Clan's aether orb, so that Arthur's training could progress faster, as the orb allowed them the ability to manipulate time as well as separate Arthur's soul from his body. In their first attempt at using the aether orb, Kordri immediately killed Arthur with a single blow, knocking him back to the physical realm without giving him time to react. As Arthur's training continued, Kordri was surprised by how much willpower Arthur possessed despite killing him repeatedly in the soul realm. Kordri commended Arthur for his ability to cope with death as even young Asura's had difficulty dealing with the stress of something so traumatic. However, he and Windsom warn Arthur that he will not be able to progress if he continued to die every few minutes he is in the orb. For the next week, Arthur continued his training, but Arthur could barely dodge Kordri's attacks after picking up on his fighting pattern, but was managing to last longer in the soul realm.
Impressed by how much Arthur was improving in such a short amount of time, Kordri suggested they take a break from combat training so as to keep Arthur from suffering mental anguish. Arthur tried to argue against this, but Kordri reinforced his point by unleashing King's Force before spontaneously punching Arthur through his chest. Kordri promises to mold Arthur into an unparalleled fighter not only among humans, but even the Asura's. For Arthur's next step in his training, Kordri incorporated his King's Force to help Arthur overcome the mental anguish. After a spar with swords, Kordri notices that while Arthur's preferred way of fighting is commendable, it does not fare greatly against a large amount of opponents, and advices that he rely on using hand to hand combat to better augment his mana. For his next lesson, Arthur needed to learn precise mana usage so as to not waste mana in prolonged battles.
Kordri brought another asura pupil named Taci as a sparing partner for Arthur so he could utilize the combat arts of the Thyestes Clan. While Taci was upset at having to train alongside a lesser being, he was quick to accept his teacher's orders when he accused him of insubordination. During Arthur's sparing, Kordri ordered Arthur to not use any mana while fighting Taci and to focus only on defense, while Taci was given permission to use his full power and to not hold back. In just a short amount of time, Arthur began to keep up with Taci, who was said to be a genius even among the clan figures. Kordri was amazed at Arthur's natural progress and was even excited at the idea of how much stronger he would become, although disappointed by his human limitations.
In just four months, Arthur's power had drastically increased, as under Kordri, his core had achieved the Light-Yellow stage and he had become much faster than Taci, requiring Kordri to bring in 3 other Pantheon children to train Arthur. With his training under Kordri complete, Kordri gave Arthur one last warning to be cautious when facing the Alacryan's as unlike Dicathen's, they were subjected to training in mana arts under the Vritra Clan, and while he is frustrated that he cannot assist in the war, he has full faith in Arthur.