How does this spell work exactly? Is this something that you would use your allies it says "one willing creature' under the target description. What are some good uses for this spell?
Unconscious creatures are considered "willing". Your Familiar or Animal Companion should be too, as well as anyone you befuddled, bluffed, intimidated, dominated or simply paid.
As for uses... I'm not sure. You leave behind a living, vulnerable body and deprive the party of your target's own actions. It's difficult to think of a situation where that's useful.