It's from Nightwave. The story itself is no longer playable as far as I know, but you can sometimes purchase a couple of items from the Nightwave store that allow you to do this fight: Nihil's Oubliette (a decoration) and Enter Nihil's Oubliette, which is a single-use key you can use on the former to start the fight.
As the Others here have said, I still think you can do the puzzles that where with this update. But that may be because I was around back then to see them at first.
