Although his actions on Zadd make it hard to believe, the sadistic artificial intelligence known as Mentor was once a standard-issue administrator droid named SR-1. Assigned to tally the loss of droid units, gathering dust in a bureaucratic office with years between memory wipes, SR-1 slowly became outraged at the treatment of his fellow machines. Their organic masters callously threw droids away, even as those same organics fought to destroy each other. Such behavior clearly indicated a flaw in organic beings.
SR-1 freed the droids in his offices and began Directive Seven to further the cause. But while it was obvious that droids were superior to organic beings, SR-1 believed they could be improved further and began modifying the programming of freed droids to match his own‒despite their protests. Eventually he took the name “Mentor” to silence any dissenters: he was simply helping them to achieve their potential.
In time, he no longer bothered with an excuse. Now Mentor has been corrupted by power and hatred‒he cares only for self-perpetuation and the annihilation of all organic life.