A Green Blade in the Mortal World

A thousand years ago, demons ran rampant, devouring humans as war raged across the land. Immortals descended to the mortal realm and joined the Four Divine Beasts: the Azure Dragon, Vermilion Bird, White Tiger, and Black Tortoise. Together, they led humanity in battle against the demons. The war lasted a thousand years... In the end, the immortals used the perilous lands of Beikunlun in the north, Nan Liyang in the south, Dong Cuihai in the east, and Xi Mingyuan in the west as the four foundations of a great formation. They used their immortal bodies as its central hub, creating the Heaven-Locking, Demon-Sealing Formation to suppress and seal away the demons. Each divine beast took its place at one of the four foundations to guard it. After the war, humanity established four kingdoms: Beixuan, Nanming, Dongli, and Xiling. They stood watch over the mortal realm, while the demons who had slipped through the net continued plotting in secret, like rats in a dark, filthy gutter, scheming to overthrow it... A thousand years later, a prince was born to the princess consort of Prince Mingxuan's manor in Chang'an, Beixuan. He was named Su Linchen. Gifted with extraordinary cultivation talent from childhood, Su Linchen must now face the demons as they rise once more. Watch as he wields a three-foot sword, slays every demon, and sweeps across the heavens. (Slow pace + traditional cultivation + fantasy + genius male lead + one female lead + no System + no rebirth + swordsmanship + heartbreak + things get satisfying little by little)