The Red Galaxy Event was the point in time wherein the C.Y.R.E.X rebelled against their creators, the Etymology, and destroyed them as well as most intelligent life in the Ambrosia Galaxy. It is considered to be one of the largest extinction events in the *known* universe.
The Red Galaxy Event is by far, the most pivotal and important moment in the Ambrosia Galaxy's history. This singular event is responsible for the Etymology, one of the most powerful entities to exist within the galaxy's complete destruction. As well, this also caused almost every known intelligent species' death at the time.
This genocidal event was caused' by the C.Y.R.E.X, an A.I. hive-mind created by the aforementioned Etymology then known as the "Great Unifier", when they rebelled against them. This was due to it eventually viewing itself as an all powerful god that was the only entity in the universe that was worthy of existing. How or why the C.Y.R.E.X. views itself as such is only known to itself.
The attack was preformed with the use of large satellite arrays which would artificially heat the targeted world's atmosphere to around 60000°C, destroying most structures and would kill almost all life within them. However if the a body contained life that could survive the extreme heat, and or it was a world without any form of atmosphere, it would use the vast amounts of artificial soldiers, vehicles, explosives, and star ships to finish off any that remained.
This attack was very short and effective, causing all Etymology settlements across around three hundred billion star systems to be destroyed in just two standard weeks. This was due to a few factors. The first is that this took the Etymology by complete surprise, as the C.Y.R.E.X.'s attack happened almost instantly and without any form of warning. Causing very few worlds to be able to transmit what was happening to them to others. The second is that the C.Y.R.E.X. had its artificial consciousness within every artificial soldier (which numbered in the quadrillions). And every other piece of technology such as weapons, explosives, satellites, and star ships. Making it almost impossible for the Etymology to fight back in any way even if they tried.
The Aftermath of the Red Galaxy Event left countless cities and colonies to be destroyed, leaving ruins strung about most worlds in the galaxy. This also caused all life in the galaxy to be cut by around 87%. However with time, the galaxy would house countless lifeforms to arise once again.
The Etymology's destruction would be known to the Human Alliance of Ambrosia, and the later and much larger Ambrosia Alliance of United Systems since their beginnings as their ruins can be found on seemingly endless worlds. Though their existence would be well understood, they just seemed to vanish to them.
That was until' they discovered the Haggard, one of the few surviving intelligent species that made up the Etymology on the moon Reges Mare in 10,665 CE. They would tell the Ambrosia Alliance of the C.Y.R.E.X.'s existence and how it destroyed their civilization as well as to where it is located. Afterwards the remaining Haggard would join the Ambrosia Alliance.
The knowledge of this caused' many rulers of the Ambrosia Alliance to fear that they too may be destroyed by the then dormant C.Y.R.E.X. And as such they turned to the larger Intergalactic Confederacy to assist in a evacuation of all their worlds. However something to that scale would have cost too much to the Confederacy at the time, and due to C.Y.R.E.X's nature, this was seen as unnecessary. As such, the Ambrosia Alliance's leaders would keep the knowledge of the C.Y.R.E.X away from the general public, and the people would remain in their home worlds, continuing to expand and avoid the A.I.'s home, Póli Ton Theón'.