Clash Between Two Ends

My heart's as dark as sin, I'm Satan's closest kin, my power held within, the light shall never win. Flames rise from down below, my throne will only grow, you mortals all shall know, your suffering is slow. A clash between two ends, each realm begins to blend, the forces that we bend, the soldiers that we send. Centuries of war, a pact, they made, we swore, no blood, no death, no gore, but still each other we abhor.