Specific to the plane of negative energy in my #TTRPG world is a form of fire that burns an unsettling, pale blue and steals all warmth around it.
@tyghebright Another +2 dagger? Meh.
A +1 dagger with an almost perfectly transparent crystal blade, alight with crackling blue flames, from which a wispy trail of cold mist trails along the ground? Yes please. And the ongoing cold damage on a failed Dex save is just fun for the whole family. Raises the question- can you quench cold flames with water?