Ron, you referenced an answer to this question on Gaming Outpost in this thread, but that answer seems to be inaccessible now, so I'll ask it again.

What is the relationship between a Possessor Demon's Stamina and that of its host? When engaging in combat, say, which Stamina do you use?

My assumption is that the Demon's Stamina is used, because Fast makes the most sense to me with that interpretation.

Hi Dave,

If the demon is doing something physical without using an ability, whether to hit someone, catch someone, or whatever, then use the demon's Stamina score.

If the demon is using an ability, see the ability description to be clear about whether Stamina, Will, or Power is generating the dice roll. In any case, use the demon's score.

However, in both cases, if the demon's score is greater than the host's, use the rules-example in Chapter 4 to see whether the host's body handles the strain of the excess. I hope it's easy to see that quite a few possible score-vs.-score rolls could be involved.

If the demon would prefer to make use of the host's score, for instance, it's possessing someone much stronger than itself, then it has to enlist the host to do so. This can happen in one of several ways:

a) The host is simply convinced or already inclined to help, in which case a roll of Will vs. 1 die might be made to see how many dice (of whatever score is desired to be used) can be enlisted in the action.

b) The host has no intention of helping the demon, in which case the demon must defeat the host in a Will vs. Will roll, adding the victory dice (up to the host's score, or beyond if the demon doesn't mind straining the host) to the demon's roll.

c) The demon simply "gives up the reins" for a while and lets the host do its stuff, in which case the demon's abilities and scores of any kind are out of the picture temporarily.

Best,
Ron

Thanks, Ron! That clears up the situation in my head nicely.