Having 1/3 of your population be slaves isn't very viable long term. At that prevalence, revolts would usually be a significant problem. The batarians get around this by implanting all of their slaves with explosives using the looming threat of lethal punishment to dissuade any would-be resistance. Despite being morally repugnant was very effective, or at least it was until I meddled at Bahak.
I wanted to use a slave revolt on Bahak as cover for destroying the Alpha relay, so I disabled colony-wide defenses and disabled all of the implanted explosives. It worked extremely well. The relay was destroyed and nearly 100,000 slaves were freed. What I didn't realize was I made a slight mistake when I disabled the explosives. It was so easy to disable them all because they were all connected to a single network. This sounds like a design flaw, but it's intentional. The Batarians made it that way to be able to instantly put down revolts. They arrogantly believed their system was safe, I took advantage of that to instantly disarm all explosives. I had assumed that this system was local and that each planet had its own, and they do but each of the local systems are connected. When I deactivated the bombs on Bahak the local system sent an update to all of the other systems. In the end, I deactivated every bomb on every Batarian Slave. It didn't take long for slaves to notice. When the sword of Damocles hanging over their heads disappeared they got a taste of freedom and they wanted more.
Now even more determined to help, I started by sending supplies, weapons, and mercs. That was just a stop-gap though. With the right planning, supplies, and time the slaves could very well over through the government and win. Unfortunately, even if we had all three it would be difficult. The Hegemony has every advantage over the revolting slaves. A direct confrontation would lead to millions of deaths. So, it was time for plan b also known as "Why don't we take the slaves and leave them somewhere else?"
It worked well the first time. The ex-slaves of Bahak have safely settled Aeia out in the terminus system. The planet's natural flora is a bit poisonous, but everything else is great. The planet still has plenty of room not enough for billions of slaves, but if we add in some of the old territories of the legion that is no longer being held the population can temporarily be spread out and settled. After the Reaper invasion, non-claimed planets are going to become a lot more common. In comparison to the citadel colonies, I've been trying to relocate this is much easier. None of those colonies had dedicated fleets. While the revolts can't hope to win an overall victory, strategic victories at shipyards and docks are very achievable.
Trying to set up the logistics of these new freed slave held worlds was what originally interested me in intervening. The Free People, what they're now calling themselves as a whole, are maximally 60% Batarians with the other 40% made up of the council races. Of that 40%, some want to return home, but the vast majority don't. For some, it's out of bitterness for being forgotten. Others, see it as exciting or a new opportunity. However, there are also the people born into slavery who have no legal or emotional connections to the Council governments.
Every Citadel race has a single government. This has been historically true for most non-Citadel races as well. The Free People forming a new multi-species government creates a big conflict of interest for the Council. Doubly so when we convince the Free People to join the legion. It's incredibly hard to keep popular power when your fighting against your own people.
As I frantically tried to get everything ready, I was notified by my scouts that the Reapers would soon be reaching the galactic rim. From there it would be less than a day before they were everywhere. Which meant it was time for the final step of Secret Savior. The new crucible had been built in secret to avoid diplomatic disputes. That meant that they couldn't be openly built attached to the mass relays as is needed. The final step of Secret Savior is a rush to connect the constructed crucible to the relays. Synchronously across the galaxy my teams towed and attached the crucible to the relays.
If the crucibles sat there for very long the scrutiny I had been trying to avoid would be unavoidable. Once the crucibles demonstrated what they could do things will go a lot smoother and we'll be subjected to less involuntary mistrust. Luckily, or Unluckily, only hours after the crucibles had been fully deployed the Reapers arrived in mass. From out of deep space they flooded the relay network as they rushed to occupy the entire galaxy. Not a single system was left without their presence. I pushed my awareness and information network to their limits. Waiting just enough to catch as many Reapers as I can, but not giving them enough time to attack the crucibles. The Reapers noticed the alteration to the relays almost immediately, but in that fraction of an instant, it took them to process I activated them.
The mesmerizing spinning rings stopped and the blue glow turned an autumn red. The red glow violently expanded outwards. At speeds far faster than the speed of light, a unique electromagnetic pulse rapidly saturated a vast section of the Milky Way.