Glowing Ossuary Part 2

The obelisk broke open and some kind of eldritch horror seems to be within. Luckily Plank is able to collapse the room it is in with a well-placed fireball spell. After some consideration, we confirm it's sufficiently sealed again.
 
We move on to try to figure out the solution to the Runes. Trin remembers the puzzle from the last time we were here. As above, so below. This opens a door which seems to lead to a treasure room. Inside is an ancient sarcophagus which seems to hold a giant. Presumably, these were his treasures. We get the lid of the sarcophagus off and inside is a giant sorcerer mummy. He has a warhammer that Trin says is magical.
 
Dan lets us know he sees Claud whenever he kills someone. He seems haunted. We suggest he try to ask Claud what is going on the next time he sees him.
 
We take the Periapt of Health (Plank) and the Warhammer of Witches (Dan) and also dump a bunch of treasures into Trin's Bag of Holding. Though we are eager to leave, our work here is not done! We find more sarcophagi on this floor, but not much else of interest. Trin sees an inscription and says aloud "As above; So below" and clears the spiritual energy in the area. We decide to clear the floors above us before continuing down. On the first floor, Carlisle easily convinces the cultists that we are not a threat and also gets some useful information about what goes on below obelisk level.
 
We get to the 6th floor and Carlisle goes for the key (it will look good for his promotion.) He is able to grab the key but then is greeted by this own mirror reflection emerging from the mirror. Dan eldritch blasts it for 16 dmg and destroys the... glass golem? Bigsby/Carlisle is able to take the key (an odd emerald skull) and use it on the elevator to gain access to 5 more floors!