The big players of the Halo Universe consists of humanity pre-covenant, humanity-post covenant (who are highly developed), the covenant, covenant separatists, Forunners, and I totally forget their names but the robot Forunners we fight in Halo 4, Humanity pre-Forunner transformation to cavemen (which is so extensive we don't even know all of it, and who were more powerful than the Forunners), THE MUTHERFLIPPLIN FLOOD, and of course the wait for... Precursors (who alone could destroy Star Wars), also I do believe there was another even more advanced civilization before the Precursors who the Precursors discovered vast knowledge from. Not even going to begin with all the other thousands of races that are rarely touched on unless you dig deep into the lore. This is just the beginning of the Halo Universe. If someone else could explain the Precursors power in depth that would be great.