Genies: Don't piss one off. Very random. Tend not to do anything nonconsensual to humans only because Spirit Bearers by and large have sworn to hunt down and kill any who do. A lot of the random magic stuff you'll find (eternal waterspout, wooden bird that flies and sings anyway) probably originally came from a genie, as payment for whatever strange thing they wanted from humans.
Nature Spirits: Are a myth, claim a fringe group that sound a lot like Flat Earthers. Have attention spans measured in weeks or months and can squish most monsters that aren't Named Beasts, and most lone Spirit Bearers, say everyone else. Their powers tend to be nature-themed, but they sometimes do things outside of theme, so they might be as unlimited as genies and just really unimaginative.
Monsters: Are evil. Look at this long list of the different kinds of evil! Goblins will straightforwardly try to stab you. Gremlins will try to sabotage things in such a way that kills you. Gunkers will try to poison food and water supplies. Trolls like to collapse bridges and power lines. Lurkers seem to cause distrust and discontent around them. Rumples preferentially attack small children. And so on.