@GreatLucifer Believe it or not, I once saw 3 "will'o wisps" in real life when I was a teen. I understand why you might feel wisps would be the wrong aesthetic for your game, so not trying to convince you otherwise, but people in swamps, marshes, or bogs do see wisps fairly commonly. In real life they are apparently caused by swamp gas from organic decay emitting photons, but they can also be caused by natural gas leaks in urban environments. They do move around and the ones I saw appeared to chase each other rather lazily. It is easy to see why ancient people believed they were alive and sentient. The ones I saw came in yellow, cyan, and a sort of pink, as if light had been split/refracted. They don't fight you, of course, but I thought you could make them passive perhaps if you wanted to give the feeling of a swamp where there is a lot of natural decay and waterlogged material. It depends on conditions, but there are many many legends of lights in swamps, bogs, marshes, and anywhere manmade where methane or other gases may be present (mines, dumps, powerplants, graveyards, etc). What I saw was rather typical, colored light globes a bit bitter than a fist. They were less than 3 meters away from me in broad daylight, so I know they were not barn owls, bioluminescent insects or mushrooms, or any of those observer-is-an-idiot theories in the wikipedia. There were 4 of us. None of us were scared because my school had actually taught us about them, they were so commonly seen around that area. Somewhat more rarely, people report wavering columns often a bit thicker than a person, but where I lived we never saw those. One new-ish theory about the column type is that tectonic strain creates piezoelectricity. I'm guessing you'd be more likely to see these columns near fault lines, but I don't know much about those. I've never known anyone who has seen the columns but a lot of my friends growing up had seen the glowing balls in or near the marsh. I'm guessing you want a less stagnant type of swamp.