Moon Phase -» like the Cosmic sorcerer of 4e, binding yourself to the different moon phases, each giving you different effects when you cast.
At this point if we don't get a "Cosmic" Warlock I might have to go and make one, ripping features from 4e's Star Pact and Cosmic Sorcerer. The Great Old One sort of did it, but 4e Star Pact had sooooooo much more flavor I feel.