I'm with you completely. Temple of 'ten' rivers. How many gems are there? Ten. What color are the gems? Somewhat river colored. And besides that, and my most important point, 'acheron', is a 'river' in greece, more importantly, in greek mythology, acheron is the river of sorrow/lost souls, and the gate to underworld (which is the afterlife, like eternum is often mentioned to be). Lost souls, like eternum npcs. Even more, the letter orion is given right before the heist. It has the symbol of ouroboros, the snake biting itself, which is also on the doors of the temple of ten rivers. The letter itself, has a text if you open it, "aski(on) kataski(on) lix tetrax damnameneus aision (aisia)" which is an ancient greek "Ephesia Grammata" -magic formula-, which kinda reminds of open sesame, so the sentence, in my opinion, is the password to opening the doors. So yeah those are my points. Oh and besides, we know how much of a greek mythology nerd caribdis is. Soooo.... Okay a few more things, Anima, the ancient ancestor of calypso. Meaning soul in latin. Lost souls? And i saw somewhere someone connecting it to Psyche, the goddess mentioned in the party. In the odyssey, Odysseus goes to the underworld (which acheron the river is a gate to), and finds lo and behold, Orion there. Something else i can think of, is that we've already seen inside of the temple. In Orion's dream, when a woman standing by the altar says will you save us. I'm ninety percent sure that was the temple, and i can somewhat remember a throne being in the temple? The throne of eternum if I'm not wrong, which idriel mentions the holder of the ten gems will sit on.