Rafe
First Post
Keep in mind that the sleep spell imposes two different conditions - slowed and unconscious - and you can only apply the orb of imposition effect on either one of those. So you can't rely on it putting an enemy to sleep and it staying there without fail, though of course even one round of helplessness can be brutal.
Not exactly. If you hit with Sleep, it's slowed (save ends). If it fails that one save, it's unconscious (save ends). You only need to apply the orb of imposition ability to the first since it goes unconscious without needing a second saving throw. However, you're right in that you can't penalize its regular end-of-turn saving throws for it to come awake and back to normal condition.
However... it would still be prone until the start of its next turn since an unconscious anything can't remain standing while unconscious (except for an ooze or something, I suppose).