I thought about the fog effect that comes from the eldritch beings and realized that could make a great effect for a build.
What if there was a 4th lamp that was an arcane lamp infused with an impetus jewel and an everful urn that could fill an area with fog instead of light?
(the fog effect seems to be more a status effect from what I can tell but not familiar with the back end code)

• Pair with an arcane lamp in the same area, and suddenly instead of a maze, you've got a gauntlet where anything could be hiding in the shadows.
• Could also pair with outdoor builds to make very foggy days at ground level, or perhaps a smoky room from a fire incident
• Pair with a room of star field glass to suggest an ephemeral realm?
• Maybe as a bonus it also puts out fire's in the area (or this could be split into a 5th lamp like a lamp of mist?)