Ok this can either go a few ways. You can have UNSC at full power and Covident at full power V.S Empire at full power and rebels at full power, UNSC/Covident (yes full power) V.S Repulic and Sepritists, or UNSC, Covident, Forruners, Flood, and anchint humans (all at full power) V.S Rebublic, Sepristis, empire, and rebels (at full power). When fighting the empire, i would give this round to Halo. At this point in time, you only have one extreamly powerful faction (empire) while the republic is scatered and not so mighty. The UNSC and Covident could pull out the arbtir, the profit, and its squads of SPARITNS in order to counter the few jedi and sith during this time period. Over all the armys of the UNSC and freinds would simply be able to out fight the empire, but it would be relitivly close depending on how many SPARTINS survive. Now with the UNSC/Covident VS the republic and seprits, i would give it to wars. There are enough jedi and sith in order to over power the Spartins and profit. The remaining armys of wars also appear more powerful that HALO for this period of time. Now the big battle. With ALL that HALO and Wars has to offer (forunners empire, all the good stuff) i would say that Halo would win. The flood would be able to consume all senian life (or most) making it easy for UNSC and forrunners to kill everything. If the UNSC would play deffence and prevent wars from entering space, you could prevent any and all attacks on halo. With the flood and covident killing all sentian life, that would allow the anchint humans and foruners to kill the droids. Anything that would survive the flood and covident would be killed off by the forruners. And in an emerginsie, the HALO rings would be fired and all halo spices would be sent to the ARK to live on. Halo wins 2/1. Sorry about spelling, i dont care.