The Powers of Faith

Within the walls of the divine, there are many rooms of various purpose and alcoves where items have been left, discarded by the Powers over existence.
Some of these rooms have the purpose of being a Hall of Power, acting as a place of office for one of the Powers. Each Hall is different for each Power, but each share a single trait.
Every Hall has an alcove where the sigils of the other Powers sit, waiting to be used to call upon another. Some choose to use these sigils frivilously, using them to have simple conversations. Others choose to not use them except in times of dire need. There is no wrong way to use them, as the sigils are there for the simple purpose of calling on another, though the Old Powers may wish to have made more use of them after their retirement.
Should one find themselves unwittingly in a Hall of Power, leaving is perhaps the best course of action, as Powers can be fickle even in their own domain and mortals do not belong in these places. Halls of Power are a place for the divine and the invited, treading lightly across the sky of immortal reaches to prevent the mortal world from seeing the actions of Powers left to their own devices while operating the threads of their own machinations.
If one stays in a realm where they do not belong, the realm leaves an indelible mark on their soul, branding them with a remnant to be seen in reflections. For some, these marks reflect shadow and darkness, others reflect the moon and the stars, but the truly unlucky reflect war and bloodshed in the mirrors of their world, unable to be anything other than permanently stained by a place they should not have found.
Mortals must tread carefully in their realm, for the borders between them and the immortal are want to change. They grow thin in places they should be thick and thick in places they should be thin, but in no place are they ever more than what they are supposed to be or less than what they could ever be, leaving mortals themselves to be the ones to bridge the gap.