Svibra are airborn microorganisms that covers the entirety of Dark Keigan. They are about a tenth of a millimetre long and are kite shaped with wing-like appendages on either side of their bodies. The existence of Svibras are thought to be caused by Ruchalus since they come surging out of the cave openings that are on the north side of Soburuke.
Svibras can move on their own, but it's their swarming behaviour that makes them noticable. They appear as black billowing clouds that move sporadically. And they will move away or towards sources of light, depending on what kind of wavelength they emit. This makes illumination very difficult in Dark Keigan as bright spotlights will be completely entombed by clouds of Svibra, forming a thick crust that is difficult to remove.