Complex sentence: Subsequently, he encountered the Tian Shan Tong Lao and other acquaintances of Wuyazi and learnt martial arts from them and became the leader of several unorthodox sects in the Wulin by chance again.
Split into simpler sentences: Subsequently, he encounters Tian Shan Tong Lao and other acquaintances of Wuyazi and learns martial arts from them. He becomes the leader of several unorthodox sects in the Wulin by chance again.