Wind Stalkers are an old and rare trick of Conjurers. Only a few hold the secrets to their creation and, even still, they are notoriously difficult to tame. Plenty of would-be Conjurers have been vivisected after their attempts to tame and create Wind Stalkers have failed.
For skilled practitioners, Wind Stalkers make for a useful tool in assassinating rivals, stealing objects, or accomplishing other clandestine tasks. One should simply be careful regardless of their skill: Wind Stalkers are particularly resentful towards those who summon them. If they were to become unbound for any reason, they will immediately seek to kill their Conjurer.
Wind Stalkers only exist so long as the Conjurer - or whatever it is keeping them in
the world of Arethil - is active. If they are unbound, they will seek to hasten their departure by murdering the one who conjured them. If for some reason they persist past this point, they generally become docile and seek out wide open spaces in which to range peaceably.
Or they go berserk and attempt to murder everything they come across, disregarding all notions of tact and stealth.
But that's rare.