Magog, the Blood Magus

Magog is a blood magus (see Complete Arcane), having becoming so merely for more ways to inflict harm and pain. He is the darklord of a gruesome domain where blood and taxes are paid in blood and body parts and horrible demons keep the citizens in line. Magog himself is not only a sadist but also addicted to causing pain. Once per month, he is cursed to experience all the suffering he's caused over his lifetime.