Just realized that the Reapers would have been successful if the star by the Mu Relay hadn't gone supernova. The fact that Ilos and the conduit weren't instantly accessible to Sovereign is perhaps the single most significant stroke of luck in the entire trilogy.
It certainly helped, if nothing else. The Protheans' efforts to make Ilos go dark, and the easy access to system disappearing definitely helped.
Dark energy can rapidly age stars. Protheans were biotic gods. What if the Prothean destabilized that star to send the Mu Relay off, in an effort to hide Ilos from the Reapers?
I think the Reapers would have a way to track the relays regardless of their positions, being their technology and all, or maybe the energy of the supernova disrupted the link with Mu.
It is hard to say when the Supernova took place an displaced the Mu Relay, as the Rachni already existed during the Prothean cycle.
I doubt that the Protheans where able to manipulate enough dark energy to let a star go Supernova. If they could, they would have used this acceleration process to fight the Reapers...... sacrifice 1 System to erradicate a whole fleet of Reapers = cosmic imperative thinking.
On the other side, it is interesting that a full-fletched Supernova could not damage or destroy a Mass Relay, while 1 single 08/15 asteroid ripped it in shreds. I know it was a big one and a direct hit, but come on... an asteroid vs. an exploding sun?
Anyway, we were lucky to find the breadcrumbs to get there. The whole Conduit Incident was pure luck on our side, but that is what the whole ME story is about..... one lucky shot can change the balance. Screwing up on rescuing Tali, or deactivating the bombs on Eden Prime in time would have all resulted in the Reapers wining. We are a very lucky cycle, well ... despite the billions of casualties.
I almost forgot to mention, that the Mu Relay alone is useless unless you know where to go.
Sovereign could have looked for the reason why its command signal was rejected by the Keepers somewhat like 40 years ago (must have been prior to Shanxi), but looking and scanning puts it into risk of being detected and would deplete its power reserves.
It knows something went wrong but does not know how to solve it, nor that it has to go to ILOS.
This is only revealed after Saren and Shepard recieved the Info from the Beacons.
If that would have happened before shanxi then think about that for a minute. Would humanity even have been affected ? Or did we have some amazing timing in showing up
We know the Reapers influenced the Rachni to wage war 2180 years or so in the past (songs of a sour yellow note aso), obviously to test the strength of the actual cycle.
I actually do not know when Sovereign realized that the Command Signal doesn't work, but regarding the Evolution Comics and Sarens backstory it is save to assume that around 2150 Sovereign increased it's effords to repair/bypass the Prothean Sabotage to the Keepers.
The human discovered the Mars Archives 2148, so a reaper Invasion 40 years before they actually did (effectively 2146) would still place the humans as a to harvest civilization, as we were capable of interplanetary space flight.
This makes us too advanced to be cast aside. We would simply be too dangerous to be spared into the next cycle, as we would have 50.000 years to develop on Mass Effect technology. The Reapers could be defeated conventionally.
The complete Harvest of a cycle takes decades to centuries and as soon as we, or any other species would touch a Relay, the Reapers would realize and send a welcome party.
That would be terrible. Hey guys there's aliens and they're here to kills us and turn us into them.
What do you think?