I wanted to make some “mood lighting” for my levels. Basically, make a particular area really dark (but not to a point that the game becomes artificially difficult), but would get brighter the closer you got to torches or other sources of light. Unfortunately, there’s no way to do that; there’s no call event that changes the map lighting. Which is a shame.
The reason I wanted to do this was because I was thinking about world-building. These ruins you’re exploring are meant to be this fiendish death trap that nobody has ever navigated all the way through: so where did all these lights come from, then? Who has been here? Do the monsters need light too, or is there something up? Just some things for the player to think about while they were exploring. Like all good RPGs, I want to make things interesting for the people playing. I’ll just have to find something else to use, instead.