Kaiju Taigu Yaosheng Na Wo Dang Lu Ding

The first step of cultivation is to make a contract with a demonic familiar. He was untalented and unwanted, until he runs into an ancient demon lord, who happens to take the form of a sexy girl with a tail! She tells him that his foundations are strong and his bloodline is powerful. But this demon is just too alluring, and everyone wants take her...