I scripted the behavior of this asset and created the prop out of an existing asset
The Mournwatch stones above the door that kicks off the "Pinnacle of its Kind" quest are meant to add a little flavor for players who love little reactive details. The stones all start out glowing and will extinguish one at a time as each demon is found and killed.
States
Incomplete (Default): The emissive on the stone is turned on
Completed: The emissive of the stone is turned off when the associated quest is completed