Miasm's body is very soft as it is made of very dense water vapor, and has a similar texture to that of a cloud, with magically suspended objects within it. Because of his lack of a proper skeleton or a ridgid exoskeleton, he can be stretched and shrunk to varying sizes. Miasm consumes harmful gases, polution, smoke, and fog so that he may clean it an add it to his own body mass. The black fog located within his stomach is currently being cleaned and will eventually become clear and white like all the rest of the smoke on his body. As time continues bits of his body disapate into the atmosphere, meaning Miasm won't get much large than his natural size unless fed a tremedous amount of gasses.

He was taken in by the College due to his unique abiliy to douse fires by releaseing oxygen-less gasses from his stomach, and was quickly assigned to a Magus named Darling in the Demon Hunting profession as Familiar with a potent ability to counter fire. As the Demon Hunter's are currently active hunting Urime, who uses fires, Miasm has been deployed.