Possession Burnout in Literature.
- In A Darker Shade of Magic, bodies possessed by Vitari gradually char and eventually crumble to ash.
- In the YA Urban Fantasy Book Series beginning with The Demon's Lexicon by Sarah Rees Brennan, the heads of The Masquerade keep Mezentius House, a hospital/prison for bodies possessed by demons, which basically keeps the demons under control (chained up) until the body decays and dies. However, in the third book, a magician makes a deal with a demon who wants to possess her to share the body alternating days and nights, hoping to stave off this trope.
- This happens to everyone who's possessed by the ancient evil spirit Tak in the Stephen King novel Desperation. Tak is so powerful that it causes any body it possesses to expand and grow more powerful, but it also amplifies any physical ailments they have. A host with cancer will die within hours, a staph infection in days and even something as simple as being easily sunburned will cause a body's skin to blister and drop off within a week, yet again leading to death. With animals it's even worse: they last hours at most even if it's a strong, healthy animal. They might even explode.
- Sir Terry Pratchett's Discworld novel A Hat Full of Sky introduces an entity called the Hiver, which is surprisingly alike in description, purpose and occupation to Garner's Brollochan. (Although Garner says his conception is not original - he has updated it from Celtic mythology. Pratchett may have read the same root sources.) However, while the Brollochan possesses beings to experience senses, the Hiver possesses beings to dampen its senses, which would otherwise overwhelm it.
- Further Discworld example: The Cunning Man from I Shall Wear Midnight, whose rage is so intense that it literally burns out whatever unfortunate person it chooses as a vessel.
- A variant of this occurs in the Dresden Files novel Skin Game. Harry's brain has been infected with a parasite which Mab is keeping at bay, in order to keep him under her thumb. If it keeps possessing him, it will cause him to degenerate wildly, starting with his brain. Except that it's not — not exactly. Rather, that's a spirit of intellect which is the end result of the thought patterns of Harry and Lash, and could be construed as his daughter. Yes, he's pregnant. None of which means that it'll be any less detrimental to him when he, ahem, gives birth.
- This happens to most living people that the eponymous Eight Million Gods inhabit, which is why most of the more benign ones inhabit inanimate objects.
- In Harry Potter, Voldemort goes through several host bodies before he can perform a resurrection ritual that gives him a stable new form. He has to resort to things like drinking unicorn blood to keep his hosts alive.
- H.I.V.E. Series: In the later books, this is what happens to bodies that Overlord possesss via the animus fluid.
- In the Hush, Hush world, it's said that this happens when fallen angels possess humans. This is why they generally aim to possess immortal Nephilim — those bodies don't wear out, so the Nephilim can look forward to an eternity of being possessed.
- This happens in Journey to Chaos when high level deities inhabit mortal bodies. Order, for instance, can possess any ordercrafter of sufficient power and piety but they all quickly implode from the strain of his power. Those possessed by Lady Chaos explode or turn into monsters. It turns out that defying this trope is the entire point of the series. Lady Chaos wants a vessel that won't explode when she inhabits it, so she sent Tasio to fetch Eric and mold him into someone who could withstand her power indefinitely.
- In Walter Jon Williams' Metropolitan and City On Fire, there's a type of disembodied spirit called an "iceman", formerly human. It possesses people so it can experience physical sensation again, but because it doesn't belong, everything feels "muted", so it wears its hosts out with physical excess. Sucks to be the host, sucks even more to be the iceman.
- In Alan Garner's The Moon of Gomrath, an ancient Celtic demonic entity, the Brollochan, is released form its prison cell by human interference. The Brollochan is an entity that lives vicariously through the senses of people and animals it serially possesses — but no host can contain it for long without burning from the inside and crumbling to death.
- Patternist: Doro the Body Surfer can't inhabit a body for more than a year without it dying, and that's with him actively, carefully looking after it. Since he generally doesn't bother, his bodies usually only last a few weeks. Justified because he's also devouring his victims' souls and needs the sustenance.
- Played very literally on rare and usually momentous occasions in Perry Rhodan. If a Cosmocrat wishes to pay the "standard" universe a visit and a 'mere' Projected Avatar (already indistinguishable from a normal life-form and potentially quite badass in its own right if challenged) won't suffice, there exists an alternative in which the entity possesses a specially prepared host body, typically drawn from a servant species of physically extremely tough and naturally long-lived cyclopean giants, which allows it to bring a significantly larger portion of its power to bear directly — but which also results in said almost preternaturally durable host body immediately starting to smolder and then burn, held together and kept moving only by the willpower of its possessor. Cosmocrats using this approach will generally arrange to have several spare bodies available because they can go through them fast even in the course of a slightly extended conversation.
- In Skulduggery Pleasant Darquesse plays this trope straight as a rod, describing in detail her organs melting whilst in the process of killing Stephanie whilst she is possessing the body of Obloquy.
- In Star Wars Legends, Palpatine's spirit possessing clone bodies made them degenerate really fast, which provided a limit on his resurrections.
- It was later revealed that this was not the case, and that someone had tampered with the genetic sample for Palpatine, which is what actually caused the clone bodies to degrade so quickly. The fresh bodies start to degrade before they are even ready for possession, and Palpatine can't fix it because even the original genetic material used as the template is damaged.
- Also, in the current Star Wars canon, Palpatine transferred himself to a clone body after being chucked down a reactor shaft on the Second Death Star by Darth Vader. However, his dark essence proved to be much too powerful for the clone body he woke up in, and his new body rapidly deteriorated from the pure dark side power coursing through his body.
- Star Trek
- Star Trek: Deep Space Nine: In the relaunch novels, the neural parasites originally introduced in the Star Trek: The Next Generation episode "Conspiracy" return and renew their campaign against the Trill. The novels state that if an individual is forced to host a parasite for too long not only is their original personality is completely destroyed, but that there's several internal damage to the host organs. After the assination of Shakaar Edon in the novel "Lesser Evil" by a Trill an autopsy is performed which shows that Shakaar had been essentially dead for several months and his body run completely first by a parasite spawnmother, then by a soldier parasite when the spawnmother left to start a mass spawning.
- When the Angels Left the Old Country: A dybbuk possessing a person for too long will kill them, as almost happens to Isaak Shulman.
