I had to make a diagram of the mystery beings’ various sensors, because not even I could get them all straight. :P
As you’ll notice, many of them can see in either infrared or ultraviolet, and the extra-special Instigator can see both. All of them also have a strange extra sense, which practically nobody in-universe knows the exact purpose or mechanics of (or at least, practically nobody outside the mysterious Borderlands; it’s unknown how many people live inside them, if any). This sense is a little weaker in the Instigator than most, nearly absent in the Ostentator, a little better than most in the Conductor, and very strong in the Postulator, which seems to be able to use it in place of sight.
(I said Postulators don’t usually echolocate before, but now that I think about it, I can actually see them using sound/radio waves in conjunction with this sense a lot, so that is probably no longer canon.)