I Was the Sun Before I Became an Immortal by Veyron Grape

For tens of billions of years, he existed as the Sun. He burned silently in the depths of the cosmos, watching civilizations rise and fall before eventually growing tired of eternity itself. Then came the collapse. The moment he became a black hole, he opened his eyes once more—reborn as a newborn infant in a cultivation world. The sect elders tested his spiritual roots. The spirit stones showed no reaction at all. He frowned slightly. It felt as though something inside him was missing. So… his spiritual roots simply grew on their own. They taught him spells. He mastered them after a single glance—and casually improved them along the way. They warned him that his killing intent was too heavy. He merely smiled. “Everyone,” he said calmly, “please die here.” He only wanted to live an ordinary life as a cultivator. But somehow, everything in this world seemed terribly wrong.