The Watcher Knight is the airborne form of the Archon; they use built-in giant rocket packs to float. There are several differences between it and the Archon though; these include its ability to float, its having only two "legs" (which have miniguns built into them), and its large prehensile tail which it uses to smash and grip things with.

In order to destroy a Watcher Knight, you must hit if with a lot of firepower using any weapon. Once it starts to catch on fire (blue fire, that is), you have almost beaten it; it should go down after only a few more shots once it is this injured. Alternatively, for a quick kill, it is possible to move in close with the jet pack for a QTE.

If you get too close to a Watcher Knight, it will grip you with its tail and try to make some holes in you with its minigun. unless you get free.

Knights mostly act as mini-bosses in Dark Void, as they are fairly easy to take down, yet much harder to kill than, say, a Silver Watcher Pawn. However, it is imperative that you stay in cover to kill a Knight, due to the fact that it can tear you to shreds with its miniguns if you stay out in the open for too long.