A skill nearly lost, world-walking belongs to those who can simply walk from parallel world to parallel world. Sometimes the What remains of the Saqalu. They still wield the awesome power they always did, but they are no longer… stable. More are born with this ability; some of the The Dream include any people who live between dimensions and subsist on the essence of dreams of others. More have it, too, and a few members of the Kin, for the most part, refers to human wizards – that is, humans with something else in them allowing them to do... More.
There’s rumor of at least one World-Walker who can also somehow walk through time, but that’s completely unsubstantiated.