See also: Adjoination, Giradians, and Fegarians (Fegra).
If the act of Adjoination is the joining of a human with a Giradian, an act that allows the Giradian to live a second life, Baron Stealth (a half Giradian, half Fegarian man) has a distorted version of that act called Co-Adjoination.
Due to the fact that Baron Stealth is a half-breed of two species that are normally genetically incompatible, this reality causes his version of Adjoination to be fatal to humans. He can Adjoin to any human without permission and he doesn’t have to be dead to do it (his Fegarian genes can override his Giradian ones).
He can use his host’s appearance for as long as he wants and when he is done with the body, it comes out of him dead as if his body was rejecting a virus.