Mormo is the Descender of Yaoon, though he failed to protect his world, and he comes to Terresia to fight the Devourer. Although Mormo talks with a masculine voice most of the time, he states that he has no gender when talking to Arche Klein after asking what he was. He also makes the point that on his home world, Yaoon, people there are naturally nonviolent and sedate, and that the people do not have an actual government, but they all "just sort of hang around". Mormo is very proud about the stripes on his back, as he says in a conversation with an Ad Libitum member. He is a genuinely good friend and worries about Kanonno and the Protagonist when there is trouble.