The Sadist God

Countless eons ago, a man dedicated his entire existence to becoming an immortal god. He succeeded. Now he spends his endless eternity tormenting those unfortunate enough to have been created by him. Of course, an omnipotent human is still a human. And humans get bored. What do you do when you've done everything you could ever desire to do and you're incapable of killing yourself? You make yourself mortal again to experience all the simple pleasures that come with vulnerability.