After Becoming a God, I Was Reborn as a Good-for-Nothing

One moment, Lin Xiuran was undergoing a heavenly tribulation under the witness of the Heavenly Dao, about to ascend as a Divine God. The next, everything went black, and he became Lin Xiuran, the foolish son of the Lin family, a cultivation clan in the Myriad Spirits Continent. He was not only foolish but also naturally slow-witted, and his parents raised him as an imbecile until he was eight. Though he could not cultivate, his parents doted on him, and he grew up in peace, safe and carefree. After Lin Xiuran arrived in this world, his cultivation began shooting up like a rocket. But can someone tell him when a battered, ancient-looking longsword got bound to his soul, and why he keeps getting pestered by its sword spirit??? A steadily leveling-up story, a feel-good power fantasy. The outline is tentative for now. The male lead is unbelievably adorable, a cute-type protagonist with a massive golden finger. In his previous life, he was a cultivation genius who focused solely on training. His combat prowess was godlike, but he was hopeless when it came to feelings. The love interest is insanely powerful, even stronger than the male lead. He has a split personality: his main personality is a human iceberg, while his secondary personality is devoted to flirting with the male lead for ten thousand years. The rest is undecided for now. I'll add more when I think of it.