Alright so:

Mausoleum is fairly spacious. We have a wide rectangular entrance with a central altar. Any offerings on said altar are pretty old, except for the doll mentioned in my post. To the left and right are slots for coffins lining the walls, and decorative carvings featuring various Mayonite/Reonite iconography such as stylized moons, roses, and Lamplighters(more on those later). On either side of the altar is a spiral staircase downwards, which likely links up on the next floor down.

Any undead are not currently visible and and coffins do not appear to be disturbed.

Lamplighters, for some clarification, are a type of low-level divine entity that serves as psychopomps for Reon and Mayon. They light lamps that lead the souls of the dead to the afterlife. In appearance they're female children who wear tall hats that have lamps hanging from them, and carry a long rod with a candle hanging from one end. There's a Halloween-ish holiday centered around them as well, and they're not uncommon as grave decoration much like angels are in the real world.