There are a number of different forms of possession that exist in Werewolf: the Apocalypse, and here I will examine and compare each. Due to space concerns we’re not going to examine the other World of Darkness games’ take on the subject (The Mind and Spirit spheres in Mage, Kindred Disciplines, the entire premise of Demon: the Fallen and so on).
The various extant methods of possession, both beneficial and maleficent, and some of their details follow:
This is the form of possession with which Garou are most familiar. Most commonly seen among Banes but occasionally seen among Wyldlings as well, this insidious Charm bonds a spirit to a mortal being for the rest of the host’s life, transforming it into a Fomor (if the spirit is a Bane) or a Gorgon (if it is a Wyldling). The host is physically changed to reflect the presence of its possessing spirit, but may look completely normal as well. In any case, the Bane has wound itself tightly into the host, and is there to stay. The host still has a measure of self-will, but all of its thoughts, feelings and desires are filtered through the lens of the possessing spirit. Many Fomori spend their existences in a losing battle of wills with their possessing Banes, but many others slide easily into spiritual and mental slavery either in exchange for power or due to simple weakness.
If a Possessing spirit is driven out of its host somehow (usually via the Gift: Exorcism) then the host suffers grievous bodily harm, usually considered roughly equivalent to 10 health levels of unsoakable damage (which, though unspecified, is presumably aggravated). The host would require massive and immediate medical care, probably in the form of magical healing, in the same turn as the possession was terminated, in order to survive (See Possessed: A Player’s Guide, p. 16). Note that humans have only 7 health levels, and the host loses any and all Powers that it might have had at the moment that the spirit is ejected… which includes any Powers that gave it extra health levels. As a general house rule, I would say that hosts whose original mortal bodies have more than 7 Health levels will sustain their body’s total health levels +3 in damage in the same way that human hosts do – that way an elephant (or, Gaia forbid such a thing should ever get possessed, a Vozhd…) is no more likely to survive exorcism than a human is. Killing the Fomor or Gorgon does not harm its possessing spirit at all, but just kicks it back into the Umbra. The inhabiting spirit is likely to use its next action to escape via the Charm: Reform, thus avoiding any real danger, though it can stick around and slug it out with Umbral werewolves or sneak around to try and possess a new host instead if it wants.
This is the Weaver version of the Charm: possession, used to create Drones, but works differently enough that it is worth separate examination. Clarification is a more thorough process – and the possessing spirit matter in the Drone may not really even be a single distinct spirit entity but rather the Drone is pulled into the Umbra and their spirit is taken apart and rewoven to incorporate guiding Weaver-spirit portions (probably of Gaffling level). Perhaps the most important difference is that unlike Possession, this process cannot be undone using the Charm: Exorcism. The process of awakening as a Kami is similar to Clarification in some respects – most notably Kami are immune to the Gift: Exorcism in the same way as Drones are, because spirit and host are not really separate entities. Also, the process of becoming a Kami requires an extensive hibernation, just as Clarification requires extensive spiritual surgery and a chrysalis stage.
In terms of the mechanics of initiating Domination, this charm is very similar to Possession, but this Charm plays out very differently for both the spirit (usually a Bane) and its host. Unlike Possession, this Charm is not a permanent bond. This Charm also does not cause the host to undergo any particular physical transformation like a Fomor would. The Bane’s degree of control is greater, allowing it to more directly guide the host’s actions (which can be resisted using opposed Willpower rolls) and speak through the host’s mouth as well rather than the slightly more subtle control associated with Possession. Perhaps most importantly, the Dominating spirit can abandon its host at any time without harming the host, and the Gift: Exorcism also works to drive the spirit away harmlessly. (See Possessed: a Player’s Guide, p. 16)
This Charm normally has nothing to do with possession whatsoever, but there is one very curious exception: the class of warrior Banes known as Scrags. Scrags possess the Charms: Materialize and Possession, but they can’t Materialize in the same way other spirits do. They have to use Possession to steal a body as a conduit for their Materialization instead (they can do normal Possession as well). Once the host is possessed, rather than becoming a Fomor, they are physically transformed into the materialized Scrag over the course of 48 hours, and once complete they are wholly under the Bane’s control for as long as the Bane remains Materialized though the host is fully aware of everything that their body is doing while the Bane is riding around in it. Once the Scrag is ejected or departs, the host returns to his normal form without any additional harm, and remembers everything that the Bane forced his body to do. I would rule that any Health Level damage inflicted to the Materialized Bane is carried over to the host’s body as well, though it does not suffer any extra damage beyond that.
One major advantage 0f this mode of possession is that the host has no way to resist the Bane’s directives once it has taken over, and another is that the Bane can abandon its host any time that it wants rather than being trapped in a permanent bond like Banes that inhabit Fomori. One disadvantage is that, if the Materialized Scrag is killed then it is forced into Slumber like any Materialized spirit whose body is destroyed. Regular possession gives Banes less control over the host, but doesn’t carry the risk of the Bane being forced into Slumber if their host gets ripped to pieces. Also, the Scrag lacks the ability to pass unnoticed among humanity like many Fomori do, and causes the equivalent of the Delirium in onlookers.
Further, Fomori have the advantage of subtlety: most spirits are very simple beings and Scrags are no exception, but possessing a Fomor gives the Bane access to the more nuanced perceptions and increased savvy of a human host to filter its own desires on the world in a more sophisticated way. Another thing that’s interesting but isn’t quite stated explicitly is that this trick is a sort of end-run around the Gauntlet: Scrags only have 4 Gnosis, thus they even if they could Materialize normally, they could only do so in places with a Gauntlet of 4 or less… and the Possession charm, which they are using to implement their Materialization, has no such limitation. See WtA Revised, pp. 285. Note that Materialize isn’t listed as one of their Charms, but according to P. 237, all spirits have Materialize unless it is explicitly specified otherwise.
The Gift: Possession
Kitsune have access to a Gfit that allwos them to possess victims for an extended duration. The Kitsune’s phtysical form vanishes into spirit and they take over the host’s body entirely. The Gift lasts until the Kitsune either leaves on their own or is cast out. The host can periodically resist and attempt to cast the Kitsune out of their bodies, but otherwise can do nothing. The Gift: Exorcism has full effect on possessing Kitsune. (see Hengeyokai, p. 170)
The Background: Ancestors
This Background allows Garou to channel Ancestor-spirits in a sort of invited, limited possession to help guide their words or deeds, or to help them access the ancestor’s wisdom. This is a case of the Garou themselves remaining in control, but merely accessing the Ancestor’s power and wisdom by inviting the Ancestor into their body. There have been cases of ancestor-spirits taking temporary control of the Garou in order to carry out their own agendas (see the Flaw: Insane Ancestor). The process by which they do so is largely similar to the Charm: Domination, except that it is instantly applied through the Garou’s link to the Ancestor, and it is quite short in duration, usually for the duration of a scene. (See Player’s Guide to Garou, p. 167)
The Gift: Spirit’s Horse
There is a rank 4 Uktena Gift from their original tribe book that allows the Garou to invite a friendly spirit to temporarily and safely possess the user. It is a much more extensive takeover of the Uktena’s body than the Ancestors Background, even though it is most commonly used on Ancestor-spirits: for the duration of the Gift’s effect, which can potentially be for several scenes. The Garou who is allowing himself to be ridden can make a Willpower roll to remain aware of what the spirit is doing with their body, but otherwise is oblivious.