This is my theory on Kenny McCormick's, a character from the show South Park, Immortality, and what would happen if His Immortality went into greater detail.
Kenny's Immortality has been shown to bring him back by using his mother as a vessel ( ? ). If Kenny dies unnaturally, whether through brute force, a curse word plague, or anything else, he is brought back. If Kenny dies by natural causes, such as Muscular Dystrophy, he can stay dead perhaps for good. When Cartman drinks his ashes, he also drinks his soul, meaning that a sickness WILL keep him dead, but also keeps his soul in his remains, not sending him to neither Heaven nor Hell.
If his remains are consumed, whether partially or whole in any form, his soul will enter the consumer, and he will have limited control over the consumer. It is possible that he can take total control, as he apparently takes over Rob Sneider entirely, as he dresses in his parka and is shown in in elementary school trying, maybe, lick a girl; he could ha