You want to do something good – do it by proxy.
When the Stargate opened the way to new worlds, Anunnaki, ancient and mysterious civilization, found out about the other races. They came to the countless peoples in the form of creatures of unearthly beauty, ancient and wise patrons. The most powerful telepathy allowed Anunaki dominate the set of star systems. Pragmatic and cruel, they see in other creatures only live instruments with which they deftly managed. Forces mindless slaves of their possessions could expand forever if one day on their way not up the hierarchy.