Arakune, is a monster that was formally known as the Scientist, Roy. Roy's obsession with the boundary forever transformed him into this creature, who is completely insane. He is so obsessed with the "Azure", that he wants to eat Ragna the Bloodedge. As time passed, he slowly started speaking more coherent sentences, and even remember who Litchi, Kokonoe and Rellius are, but was brainwashed by the latter.