Mordred

Mordred (モードレット) was a member of Cult of Diablos, being the 9th seat in the Knights of the Round. However, he was killed by Shadow and the Shadow Garden.

Personality
Like many high-ranking members of the cult, Mordred is a delusional psychopath. Completely convinced of his own invincibility, he views fights as being beneath him and instead prefers to just casually chat with his opponents, during which he was a tendency to even give away vital information. When he was pushed into a corner, however, Mordred underwent a villainous breakdown, slipping into denial and absorbing Ragnarok's power in a desperate attempt to get out of the situation.

Overall, as described by the Shadow, Mordred is nothing more than "a mook who's all bark and no bite", addting that the only thing that he absorbed from Ragnarok was its stupidity.

Return to Earth
Following his death, Mordred's severed head was transported to Earth where it was found by Akira Nishino. The mad scientist intended to use it in his experiments by injecting 'Natsume' with his blood but was assassinated by Yuka before he could do so. It is unknown what became of Mordred's head afterward; whether Beta took it back with her to the other world or left it behind when she was forced to drop much of her loot due to it not fitting through the portal.

Powers & Abilities
He was a skilled swordsman with the use of an legendary magic sword. however, he was stood no chance against the forces of the Shadow Garden forcing him to summon Ragnarok. Despite his desperate actions, he was still not able to best Shadow even when get power by eating Ragnarok's flesh which is still a pathetic measly power.

In the web novel, he was able to heavily injure Epsilon in one-to-one combat; although he caught her off-guard.

Trivia

 * Mordred is based on the knight Mordred from Arthurian legend.