Sirian technically-advanced humans who created a new human race with a limited life-span of 100 years, which also bore barbaric traits that tended toward degeneration and cruelty.
This new human race, which exists on Earth today, was created to protect the Sirians as they had lost the ability to fight through self-manipulation when they were previously living in the Lyra star system.
The reason for the new human races' limited life span was because the creator-overlords feared that they would band together and annihilate them. Eventually, their fears became reality, and for this reason new methods had to be found to bring the genetically-manipulated races under their control once again, although it meant that these goals would have to be achieved through radical extermination.
Since the creator-overlords were more powerful than the genetically-manipulated humans those found but one recourse and that was to flee, which they did with help from benevolent supporters in the Sirius regions. At the same time, these supporters secretly decided to exploit the genetically-manipulated people for their own use.
Two large, genetically-manipulated groups of humans fled from the Sirius regions and settled in an area on the other side of the galaxy in the Nisan star system.
Some rebellious humans had also already been banished to the Sol star system.