Drones are lesser Demons with a higher intelligence then most Rouge Demons. Drone's are born from Humans who choose the path of a Demon to further explore the potential of their lives, more interested in immortality then power for the pursuit of of more.
Unfortunatley for them, they are far too weak to sustain the Demonic power and lose most of their morality and humanity. They are manipulated by the act of sin they commited, which in this case was Greed.
Drones are more highly intelligent lesser demons that normally spawn from intellectual seekers who seek to outwit life by using immortality to pursuit a greater mind. Drones lost their morality after choosing the path of the demon and they take form of a robotic life form that personifys the structured and mechanical personality of the average drone.