The Primordial Emperor

After a ten-thousand-year war, Emperor Li Haoran fought against the extraterrestrial demons for love and the mortal world, losing all his close brothers in battle and shattering his own soul across the stars, falling into an endless cycle of reincarnation. Ten thousand years later, he is reborn as an ordinary outer disciple of the Qingyun Sect. The Great Wilderness is divided into the Heavenly Realm, the Mortal Realm, and the Netherworld, with countless races in conflict and remnants of the demons secretly stirring up calamity. Although the Heavenly Emperor Hongjun and the Netherworld Emperor Mingdi possess the power of great emperors, they are bound by the shackles of heaven and earth to their own realms, helplessly watching the mortal world suffer. In his youth, he laughed and caused trouble with his brothers, trusting them with his life, experiencing both passionate camaraderie and the heart-wrenching pain of parting. When his incarnation dies and falls into the Netherworld, he fights through the Six Paths of Reincarnation to return to the living; he cultivates to become a Great Sage and ascends to the heavens, crossing the perilous Hongmeng Passage to return to the mortal world. From Foundation Establishment, he fights his way up, crossing the Saint, Great Sage, Quasi-Emperor, and Emperor realms, breaking the shackles of the three worlds to ascend as the Heavenly Emperor, then stepping into the Quasi-Wilderness, the Great Wilderness, and finally eternity. His fallen comrades gradually awaken, and bonds of love and hate span the ages. When darkness once again presses upon the world, he joins his brothers and loved ones to defy the heavens, sweeping away the demons with an invincible stance, giving everything to protect this hard-won mortal world. — Description from novelcodex.org