Complex sentence: Perhaps not coincidentally, they are three of the Chosen who have retained their modern power and authority the longest, and so far only Semirhage has been discovered by the Light, having been taken prisoner by Rand Al'Thor in Knife of Dreams.
Split into simpler sentences: Perhaps not coincidentally, they are three of the Chosen who have retained their modern power and authority the longest. So far, among the three, only Semirhage has been discovered by the Light, having been taken prisoner by Rand Al'Thor in Knife of Dreams.