Glistening in the light of Acheron, the crystalline structure of the Atrium is a fragment of Earth, carried across the void; a snapshot of green and blue amid the pale tans and reds of Tarterus, a promise and a dream.
A powerful wizard that the PCs encounter is completely silent. He does not speak and cannot be heard as he moves. Even his spells are silent, but his magic is just as potent.
He has a tendency to summon invisible chairs, place foes in invisible boxes of force, and other "mime tricks".