best magic spell in the game. does no damage

[NoRegrets]

candlelight or magelight.   in the dark recesses of dungeons and caves this will open up new pathways that are covered in darkness and show you the unseen.  along with that magelight will stick wherever you cast it, meaning you can see further down the path without actually going down it.  in my companions quest ;last night the enemies went after the light asking if there was someone there.  making it easier for me to pick them off with a bow in sneak position. any ideas on other uses for magic that aren't what they are ment for?