Jade Key

Ren Xi, a streetwise youth from the Stick Gang, just wants to coast through life. He's always worn a jade pendant left by his grandfather as a family heirloom. That is, until he's hunted to the brink of death by a rogue cultivator one night, and he learns the truth: the pendant is a key, the door is beneath the old street, and behind it is sealed the ancestor of the Duan family, who fell into demonic cultivation forty years ago. The rogue cultivator organization wants to open the door and release the ancestor. His grandfather sealed the door with his life back then, leaving the key to Ren Xi. A talisman for protection, an escape array, and an offensive finger charm—the old Taoist only taught him three survival tricks. The rest of the path, Ren Xi has to forge on his own. From a coward who could only take hits, he's forced to become the gatekeeper: the jade is the key, locked beneath the old street, and no one may open it. When someone asks Ren Xi, "Aren't you afraid?" He thinks it over: "I am. But the jade is with me, so the door stays shut." — Description from novelcodex.org