Fae

The fae are a race of nearly ghost like entities sharing a lot of characteristics with elves in some legends. In another sense, you wonder if they aren’t somewhat like wood nymphs, deities, or lost spirits. The fae can move very fast and are virtually undetectable especially in forests. They can also travel to an ethereal like alternate realm but only in their homelands or at least semi magical forests. Upon reading the description, you figure they share some similarities to the legendary Valkyrie as well, especially when it comes to combat.