The Traveler evil? Probably not, a coward and in it only for itself? Most likely. When the darkness hit the fallen houses the traveler just up and left because it didn't think they could defend it anymore. Some lil clues in grimoire and such makes me believe that the traveler was going to abandon us too when Rasputin crippled it... So it all leads to perspective, but in the end the traveler is just looking for a meat-shield.