Light is DarkEdit
The character’s eyes transform; he now sees by the absence of light. Complete darkness is for him what bright light is for normal people, and he suffers no penalty from low light.
Drawback: Contrariwise, bright light is to him what complete darkness is for normal people - the character is blind when directly illuminated, and takes penalties for any task that requires looking at things that give off light. Characters with this Umbra are forced into a largely nocturnal existence.