Lü Dongbin
According to one story, Lü's teacher Zhongli Quan became an immortal and was about to fly to heaven, while saying to Lü that if he kept practicing the Tao he would also be able to fly to heaven himself very soon. Lü Dongbin replied to his teacher that he'll fly to heaven only after he enlightens all the sentient beings on earth (another story says all his relatives). According to the book "The Eight Immortals Achieving the Tao ()," in his previous incarnation, Lü Dongbin was a Taoist master and the teacher of Zhongli Quan.