How Did the Peach Core I Threw Away Turn into a World Tree?

Chi Yi has a tail ring that he can't lose. There is no panacea or ancient inheritance in it. There is only one peach blossom tree that has been withered for three years. There is an extra book of exercises "Bagua Yantian" and an inexplicable title. Later someone told him: The peach stone you threw before grew into a tree that supports the whole world. Chi Yi didn't take it seriously. Until the first being who claimed to be a god knocked on his door.