When a Manifestor creates manifested matter at zero distance, and the matter is of the ‘carapace’ or ‘shell’ or ‘symbiont’ forms, and there’s no separation between the skin and the manifested matter, the body may become attuned to the manifested matter, and the matter actually changes the body toward the appearance and substance of the manifested matter. This can be fatal, such as the student Steeljack, who died when the parts of him that had become metallic were rejected by the parts that stayed normal. In other cases, it can cause an inhuman appearance, in which case people talking about it usually call it GSD, since it has the same effects, or simply an appearance different from the one the person started with, such as Beltane and Mega-Girl, who are using MATD to become female.