Due to the war both sides were built and trained to fight. A millennia of war had forced them to evolve. All fighting for their survival under different factions and laws abided by opposing sides. One side implores freedom and equality. The other ruled by tyranny and fear. Together they are all a part of a whole population.
With fear and blackmail floating among the ranks the followers of tyranny not only fought for their cause. They fought amongst themselves for rank, power, and even their lives. Over power with fear and use truth to your advantage. These beings never tire of a fight.
Among them one who enjoys the fighting, wonders if he truly believed what their leader taught. "Peace through tyranny." Unlike his counter parts he does not see death of the innocent justified by their quest. The war he admits to enjoy, the unneeded tortures and deaths endured by captives, are wearing on him. Breaking his resolve, his morals deteriorating with it. His pride is too large to allow him to submit to the other side and preserve his sanity. For now he must endure the screams and pain and hold fast to his rank. Hide his doubts and just stay alive.