Dealing with Possessed Creatures

[Quintain]

Ok, so our party is having to hold a large room (2nd Temple of Orcus in Rappan Athuk), and we've sealed off the doors and put a forbiddance down to deal with the teleporting effect.

The GM has ingeniously found a way in via possession and earth gliding elementals (shadow demon possession).

We have some low level paladins that wanted to join the fight and we allowed them to be present during the consecration and hallowing of the temple, but they are proving to be a vehicle by which the enemy is wreaking havoc (relatively speaking).

So, firstly, how does one deal with possessed creatures. Can the possessing creature be damaged in any way without hurting the host?

What are the entrapment spells, etc.

Looking for suggestions. They are attacking us with waves of weaker creature trying to disrupt the spellcasting of hallow to burn our consumable abilities before hitting us big at the end.

I'd prefer the ability to hedge them out of the room vs. having to deal with them when they enter if at all possible.

[Skylancer4]

Things like Protection from Evil (preferably in Aura form or as an enlarged magical circle, in your case)?

Prot Evil wrote:

Second, the subject immediately receives another saving throw (if one was allowed to begin with) against any spells or effects that possess or exercise mental control over the creature (including enchantment [charm] effects and enchantment [compulsion] effects, such as charm person, command, and dominate person). This saving throw is made with a +2 morale bonus, using the same DC as the original effect. If successful, such effects are suppressed for the duration of this spell. The effects resume when the duration of this spell expires. While under the effects of this spell, the target is immune to any new attempts to possess or exercise mental control over the target. This spell does not expel a controlling life force (such as a ghost or spellcaster using magic jar), but it does prevent them from controlling the target. This second effect only functions against spells and effects created by evil creatures or objects, subject to GM discretion.

Also Sessile Spirit spell. Antimagic field in a pinch too. Sure it blocks the forbiddance, but it blocks all the magical ways in too, as well as preventing ongoing effects from functioning. So safe on that front. Better yet, make a magic circle vs evil focused in, cast AMF to disable the possession, communicate with the elementals what is happening to them (possessing spirit shouldn't be able to see/hear anything due to the AMF theoretically, it is surpressed). Ask them to follow the person with the AMF over to the circle and to stand there while you attempt to release them from the possession. Have the AMF person walk out of the circle and have the possessing spirits end up trapped inside the magic circle. Just make sure the circle is in the corner so you can tell them they needed a "time out."

My connection is crapping out so I can't look for more, but those are probably the most easily accessible/effective.

[Slithery D]

Dispel the possessing effect.

Banishment or Dismissal to send them home.

[The Skeptical Gnome]

The spell aspect's already been covered above, so if you guys don't have those spells handy, I suppose I'd suggest a net...?

[Quintain]

Unfortunately, a net does not stop them from jumping bodies.

[Pizza Lord]

Shadow demon possession uses magic jar and that spell has huge limitations. The possessor can only sense life forces, it cannot target a specific life-force (other than a 4 HD range, or determine if a soul is positive or negative). If a target passes, that whole turn is wasted and the target will always succeed. The possessor doesn't even know why it failed (whether because the target saved or is protected from evil, or worse, is vulnerable but is currently standing near someone with magic circle or a similar radius effect and next round might not be immune to possession). This is a terrible situation to be in if you have a bunch of similar HD life-forces in your radius. You can't tell who, what, or where they are, whether they're in the room or outside the room (though you do need line of effect), or whether they've never saved against you, saved once, or saved 20 times.

If there's 6 potential targets, you can try and take one over, the GM rolls randomly (and secretly), if you fail, you can try again next round but if that fails you don't know if it was a previous target that already saved or if you tried to take over a new target but that one saved. You could fail 4 times in a row and it could just be because you keep randomly trying to take over a target that saved once and you will just get told, "You failed." You don't know if there's still 5 valid targets or if 4 have saved and you only have a chance at 2. That's assuming the GM is doing things by the book, obviously if a scene or encounter heavily hinges on a certain flow of events then maybe things will get hand-waved.

There is a spell called possession and greater possession which the rules appear to be attempting to switch magic jar effects to. Because magic jar is so unwieldy, let's assume your GM is using the option for incorporeal possession from ghosts and shadow demons to be greater possession.

Like others mentioned, protection is a great help. Shadow demons are also noted as being affected by sunbeam and such spells for driving them from hosts. This strategy of course depends on in-character knowledge, so it may or may not be available to your specific PCs.

Since shadow demons have no bodies, when expelled from a host a likely ruling in magic jar's case (assuming there is no receptacle to go into) is that they will appear adjacent to their former host. In the case of possession (greater) rules, this is definitely what happens. It also happens if their host is killed. So if you do have to kill one of the possessed creatures, at least the shadow demon will 'appear' in the area and your party will have a fair chance to finish it off at least.

Another thing to remember, is that the possessor can only leave if the host dies, the possession duration ends, or they spend a standard action to do so. Since it's a mental action, they can do this if the host gets paralyzed or held, but otherwise if the body or mind gets incapacitated (such as stunned or dazed or unconscious) they can't leave. This means if you knock that host out (a good idea if they possess an ally) with nonlethal damage or just putting it into negative hit points, there's not a damn thing they can do about it. As far as I can tell, that possessing soul/spirit/entity is knocked out just like any other creature, so no jumping around. This should buy you plenty of time until the possessed body is either healed or regains consciousness or bleeds to death and dies releasing the possessing life force.

That's a good way to buy you time to deal with the other problems one at a time, especially if you know the shadow demon will appear next to the host when expelled or attempting to leave (unless they attempt a possession from the host.)