You're just about right about that, Shien; unconscious creatures do move their souls to the Spirit Realm while asleep, only in this case they are indeed unconscious, and thus don't dream but merely soak in the abundant energy of the Plane. There is another difference, though: since the creature would be unconscious, meaning that not even its subconscious mind would be active to form a dream, the creature would not be [I]in[/I] a dream in the Spirit Realm. Instead they would go to the part of the Spirit Realm referred to as the Psyche, which has other rules applying to it than the dreams... such as other creatures being able to go there through the raw Spirit Realm and, as discussed in our recent PMs, unlike in a dream, if one dies in the Psyche one dies in Reniam as well. So in addition to the purely medical dangers of unconsciousness, one can also be killed in the Spirit Realm in the Planes.