Originality, unfortunately in ANY comic of an adventure status is extremely difficult to do, and yet, by changing just enough elements, you create a whole new form of originality.
Obviously, Landis looks and feels like Highlander...but did Highlander have characters who could control fire? Characters that grow to a "hulking" size and destory half the city? Characters that make jokes and act like Jay and Silent Bob?
My point isn't that the story itself is original, or at least wholly original, but in today's standards, they don't NEED to be.
Although, I don't know, destroying the human race so that the Everlasting can finish their battle without them is (in my mind) a very original concept.