I was stuck on this one for a little while. The reason I got stuck is because I didn't realize you could grab an orb out of a lantern that was in motion. If you're still stuck after this, ask for some specific advice and I'll try to help! :)
I assume this is the room with the lantern track running up the left side? Yeah, I thought that one (or at least the way I finally solved it) was a little cheap at the end (crossing back to put the last orb in place, not walking to the door).
The only tip I'll give is to say that the method by which you bring back the next to last orb, not the last orb, is crucial.
Have some PapaSauce. He's doing a walkthrough for all Moths as well, he just has to do Purgatory before he does them though. --- Home Theater Setup - 55" Samsung LED-LCD / Bose - Lifestyle V25 HES / 500 GB Slim PS3 ICU Clan - ICUClan.com