So, suppose Ozai wins his energy bending duel with Aang, and steals his avatar powers (which would need a little hand-waving, admittedly). In that position, I could easily see Ozai demanding worship.
Of course, he'd find that gaining the powers didn't actually make him the Avatar, it just created an horrendous spiritual imbalance, making him a magnet for trouble. He'd probably end up dying in a vain attempt to master the storm, with Aang trying to save him from himself.