Having decided to return to the center of the known universe, Jiang Fei did not spend more than a week on Earth. What little time he stayed for was spent with his parents before he left again.
Since the danger in outer space was beyond anything earthly, Jiang Fei decided to not bring his parents along with him. As his stepsister, Shang Guanqi chose to stay behind to protect and take care of their parents.
Everyone else, including the very-human Si Tuying who was the weakest of all the girls, insisted on going with Jiang Fei on his adventure. This time, Jiang Fei could not think of a reason to not bring them along.
Just like the last time he left Earth, Jiang Fei still did not have a turf of his own. That being said, he was not without power. Right now, Jiang Fei may not be a space emperor, but his combat power was so strong that he wouldn't die so quickly, and could still spare some strength to protect the others.