Light was a spell acquired and used by Kain during the events of Blood Omen: Legacy of Kain. It was found in a shrine located next to the first Bat Beacon, shortly after leaving the Pillars of Nosgoth. This spell enabled Kain to summon a magical light, harmless to vampires (unlike natural light), that illuminated darkened areas, allowing Kain to see the switches and dangers hidden in the shadows more clearly and proving itself helpful for solving certain puzzles.
Like many of Kain's Blood Omen spells, Light is not seen in further games.