Darth Sion was a shattered shell of a living being, at least physically. Held together by the dark side of the Force and the sheer strength of his own will, his skin, and indeed every bone in his body was a mass of splinters caused by injuries far too numerous to recall. The result was constant agony, and the Dark Lord of the Sith drew upon that agony to feed his emotions, which in turn fed his control over the Force according to his creed. As a Dark Lord, his power was enormous, and his will was challenged by none that still lived.