How I Stopped Worrying and Learned to Love Eberron
Mark of Shadow
This dragonmark, associated with elves, obscures reality and gives the bearer varying degrees of clairvoyance. House Phiarlan and House Thuranni use their marked heirs to publicly entertain through art and physical pleasures, but it is a public secret that they both run networks of espionage and assassination. Powerful heirs can literally walk through shadows.