The Serpent Demon's Redemption

Owen, an evil serpent demon reborn and demoted River God, vows to renounce evil. He descends to the mortal world, performing good deeds: practicing medicine and slaying demons to repair his dragon body. He saves Celia Shaw, with celestial demon power, taking her as his disciple. Owen exposes the State Preceptor as Sardor, a lust demon plotting demon realm invasion. Celia Shaw sacrifices herself to seal the portal. Owen slays the celestial demon, transforming into a righteous true dragon.