My Archrival Is Actually Me

One day, the world suddenly changed. First, a huge crack split open the sky. Countless animals and plants turned into terrifying monsters and rampaged through this shattered world, slaughtering everything in their path. Earthquakes, tsunamis, tornadoes, blizzards, volcanic eruptions... One natural disaster after another struck as humanity struggled to survive the apocalypse. Amid despair and fear, a number of new humans with special abilities appeared. * Spiritual qi revived, and the world was transformed. Shen Ling gained the ability to summon beings from other races and let them possess him so he could use their powers. Gods, monsters, angels, elves, demons, witches... Humanity seemed so insignificant before these species, as tiny as ants. * Legend speaks of the Four Apostles. They offered their souls to an evil god, gained immense and wicked powers, and turned against humanity. The foremost Apostle was named Ling Sheng. No one had ever seen his face. All they knew was that he always wore a pitch-black cloak that hid half his pale face. Wherever he went, torrents of blood followed, leaving corpses strewn everywhere. * Shen Ling and Ling Sheng were enemies. The other wanted to destroy the world and wipe out humanity, while Shen Ling wanted to protect the world and its people. But when another evil Apostle ambushed Shen Ling, his usually cold and merciless nemesis suddenly acted strangely. He killed the Apostle, then carefully gathered Shen Ling into his arms. For the first time, his dark, indistinct cloak slipped from his shoulders. Shen Ling saw his face clearly. Pale, gloomy, beautiful, like a shattered, hopeless flower among thorns. The expression on that face, nearly identical to his own, was crazed and sick, and its ink-black eyes were filled with twisted, burning love. "Shen Ling, let's descend into hell together," he said. For the first time, Shen Ling reached out to touch that sinister, sickly face, and gently said yes. * I don't love this world. But I love you. * Selfcest, a deranged, twisted villain top x kind, upright savior bottom Their faces are almost exactly alike, but one looks sickly and gloomy, while the other looks pure and aloof. The top is taller. There is a reason the top is mad. He comes from a parallel world, where the first half of his life was identical to the bottom's, except for one fork in the road. Theme: Self-love