Woman with male harem/reverse harem
 
Their civilization was as old as time. No one knew where they came from or how long their kind had existed, but once they gained the knowledge to leave their home world they spread throughout the universe like a plague. They were the most cunning of predators. Their intelligence was only exceeded by their avarice, their narcissism, and their deadly charm. 

They were a plague, a blight upon the many civilizations of the universe. Sweeping across the cosmos, they laid waste to all who opposed them, conquered any who dared to fight them, took what they pleased and discarded it once they’d enjoyed their fill of it. 

In time the tide turned against them, however. The people of the conquered civilizations banded together and fought back, defeated them, and then banished them to a small corner of the universe where they could do no harm to anyone beyond themselves. The Watchers were sent to guard them, to make certain they were never again a threat to other intelligent life forms. And for a time they were contained ….