Lewin Tilwald is a Breton rogue and is one of the three adventurers falling for the traps in Xedilian. He falls during the first trap during the quest Baiting the Trap when he and his two companions, Grommok gro-Barak and Syndelius Gatharian enter the fort.
Sheogorath sent the Hero to Xedilian to attune the Resonator of Judgement in A Better Mousetrap. Once this task is completed, this next quest begins and the Hero must choose traps for the adventurers to fall in.
He will either die or go insane in the first chamber, depending on the player's actions.