What if you left the Bungie characters alone, but changed their roles? What law says that what Bungie calls Pfhor need to be Pfhor? Why are S'pht the only possible role that Bungie's Compilers can play?
What if you came up with an entirely new storyline, using Bungie's environment, but not related whatsoever to the U.E.S.C. Marathon? Would people play it?