Why did Han Xin bury his mother alive in Jiulishan?

Mr. Feng Shui told him that there is a hole in this mountain. If you can bury your parents here a hundred years later, you will surely win the world. So Han Xin lied to his mother and buried her alive, but because of her mother's dying struggle, she fell into the second floor of the cave. If she was on the first floor, she would be the master of the world, but on the second floor, she could only worship the emperor, but she could not be the son of heaven. As a result, Han Xin really only succeeded in waiting for the son of heaven. . .