Djinn = demon. In the Jewish folkloric tradition, King Solomon (Shlomo ha-Melekh) imprisoned demons in a vessel of brass. In the Muslim tradition, King Suleiman imprisoned djinn in a vessel of brass. They’re the same exact thing, seen through the filter of each religion’s cosmology.
The main differences between the Big Three on malefic entities is whether they have free will and thus a redemptive capacity, their range of abilities, and their creation-myth origins. But that’s all theory; in practice, all agree they’re big trouble.
Unfortunately, interest in djinn among magic folk has become one of the new fads. And it’s a particularly annoying one.
Djinn are not “demons but nicer, and with an exotic mystique.” That’s wishful thinking, and has a rancid touch of orientalist douchebaggery that its wise to be on guard against.
Practical metaphysics is not the Monster Manual. There’s no need for more flavors of ookie spookie, particularly when the new flavor of month isn’t even truly justified in source texts.
It’s not that there may not be additional species of critter out in the spiritual planes, but faddism is a danger and bad research often leads to bad outcomes.
