Within days of this 'war,' the Forerunners would have largely mapped the major and most population centers of the G.F.F.A using a combination of their own slipspace drives (which are capable of extra-galactic travel and capable of scanning the complete DNA pattern of life 14,000 light years away) and the subverted intelligence of composed species. Within weeks, Forerunner ancilla, given the sufficient time required to disseminate Star Wars' computer language and OS, will access the Holo-Net and preform such function as: mining data, ex: the locations of missing planets to add to their ever-expanding star charts, distributing propaganda promising a better future under the stipulations of surrender, all the while simultaneously hacking the Republic/Imperial/Rebel/C.I.S databases for enemy movements (considering that Forerunner slipspace drives, cable of traversing the entire Milky Way in hours, are not shackled by hyperspace lanes, response times to Star Wars invasions will be swift and brutal). Concurrently, ancilla network will likewise attempt to access the Droid computers of the C.I.S, turning their own mindless droids against their erstwhile allies.         Ground engagements against Star Wars would be slaughter-fests if the Ecumene choose to deploy their Seekers, mecha's capable of matching even Gundams in terms of sheer physics-breaking awesomeness. Instead, to slash costs and avoid over-spending on their military, the Forerunners abhorred violence as it conflicted with the Mantle, the Ecumene military will opt to use the War Sphinx, an already outdated machine at least 10,000 years old compared to it successor the Seeker.   At 10 meters by 20 meters long, the heavily outdated War Sphinx will dominate naval and terrestrial engagements against Star Wars' military. Capable of deploying and shooting down hapless AT-ATs from high orbit, while simultaneously dogfighting with T.I.E fighters and X-wings, these antiques of Forerunner military hardware will leave onlookers in awe as their weapons carve divots, canyons, and create explosive blasts visible from orbit, without optical enhancements.   A single War Sphinx was regarded as a unit with enough firepower to level continents and wipe out cities, which is rather repetitive considering Forerunner cities spannedcontinents. The worst part, besides from the fact that Seekers could chew through dozens of them, was the fact they were often used as escort duty for Forerunner ships.   Hell, the Ur-Didact wouldn't have to resort to his War Sphinxs, the approximately ~ 61,000,000,000,000,000,000 strong sentinel army that composes Onyx would double as both tools capable of engaging enemy personnel, armor, and star-fighters. What's worse is the fact that in Halo: Ghosts of Onyx, an abandoned Onyx sentinel factory had the capacity to construct one sentinel every six seconds. Assuming a minimum of 100,000 years, its actually more considering that the Shield World Initiative was proposed in 110,000 BCE, that would be the equivalent to 516 billion sentinels. Onyx Sentinels, capable of orbital interdiction, will truly show the meaning of the word 'numbers' against T.I.E fighters.    Likewise, Forerunner ground ordnance would likely be more than a match for blasters in terms of energy generation and power; fully charged boltshot rounds, a weapon designated as a side arm in the Forerunner military, were capable of incinerating fully shielded Spartan IVs, titanium armor and all; even a single shot from a Z-750 special applications sniper rifle is capable of achieving the same results even when hitting a body's extremities.   Even worse is the fact that with their hardlight constructs and precise atomic transmutation, even the most ****y of Forerunner infantry (Promethean Knights) were capable of producing support units from dirt. Literally, Halo 4's Promethean Knights army, the equivalent to a bat-****-crazy Ur-Didact building his army out of 'Forerunner legos' was capable of producing Crawlers, within seconds, from DIRT.   They are, pun intended, dirt cheap.   The Forerunner equivalent of casual wear, was capable of effectively rendering them biologically immortal. 'Dumb' ancilla subroutines were capable of regulating the decay of the Forerunner genome against biological senescence. Even lethal radioactive bursts from suns were nothing to the Forerunners, as their 'skins' were capable of regenerating damage done to Iso-Didact's DNA at the same rate harmful gamma rays were destroying them. Essentially a post-scarcity civilization, the Forerunners rendered disease extinct, as their suits were capable of isolating potentially harmful material and destroy via nano-machines.   The Forerunners were also master geneticists, the Librarian, a brilliant Life-Worker, up-lifted species left and right. I wonder what happens when they get their hands on the Jedi and begin reconstructing midi-chlorians. I shudder to think of what would happen to the Star Wars universe.   The Composer, a device designed to digitally convert organic brain patterns in a process disturbingly similar to Microsoft Word's CTRL+C followed by CTRL+V (copy-paste_ function, was designed to specifically implant a digitized mind into a new cloned body. Forerunner kill to death ratios will be astoundingly high, considering their effectively revived from the dead.   Star Wars' entrepreneurs and business men that collude with the Ecumene will be left gawking stupidly as a Forerunners miners casually mass-scatter planets 'a la Death Star style,' induce stellar collapse in one system, while conversely pumping billions of tons of Hydrogen in another star "fending off stellar collapse."   Forerunner industry grossly outclasses Star Wars by orders of magnitude, considering that conservatively, using the old canon dimensions of 160 km diameter for the Death Star II, the Onyx shield world's micro-dyson sphere, one out of thousands, required as much cubic material of volume to complete as producing a Death Star II, every five minutes non-stop for 8000 years. *This wasn't even a secret project as it was a highly publicized political battle between the Ur-Didact's Shield Worlds and Faber's Halo Arrays.*   With regards to naval warfare, even with their vaunted 'biggatons,' Star Wars has shown no way to weaponize space-time itself. Food for a thought, one of the final battles between a heavily depleted and bled Ecumene had an admiral commanding 700,000 warships. Scaling from the War Sphinx escorts conceivably has the Foreunners reaching giga-to-tera tons of power output. *For reference, the quinary or quaternary particle array guns (which the Forerunners regarded as anti-aircraft weapons) on theMantle's Approach were capable of vaporizing a fully shielded Strident Class frigates 500 m long.*   Let's add a bit more salt to that injury shall we.   Forerunner naval doctrine evolved beyond the point of just your typical sci-fi battles that consisted mainly of 'WWII in space.' For instance, the Battle at the Greater Ark involved a battlezone 6 million kilometers in diameter, its safe to say Star Wars is hopelessly outranged, and this is under the assumptions that the Forerunners would be willing to come out of slipspace. Strategically, all the Forerunner navy would have to do is sit in slipspace and nuke the hell out of any Star Wars fleet daring to challenge them with impunity and sustain virtually no casualties except for maybe cleanup operations and boarding actions.   Even then casualties sustained when boarding are dubious at best, as Forerunner suppressors were capable of disabling technology, ancilla, and even neurological activity throughout an entire ship.   Should the Forerunners want to 'fight like men,' several classes of Forerunner vessels possessed  esoteric technology ranging from bafflers, capable of locally warping space-time, thereby bypassing turbolaser firepower, dazzlers used to create false sensor readings, and even remotely generate slipspace rifts capable of bifurcating even a 29 km supercarrier in Halo: Reach.   Yeah, Forerunners are beyond the capabilities of the Empire to handle. The only civilizations that beat them are ones that possess more hax than they do, and there aren't alot.