At an unknown point in time, Yang invented the technique of Airjitzu and would later take several students under his teaching, he later discovered the Yin Blade that can make everything Immortal, while testing it on himself, he along with his students were converted into ghosts.
Yang was mentioned by Misako to be the creator of Airjitzu.
During the Ninjas' stay at the Temple to locate the Scroll of Airjitzu, he threw many obstacles (the fears of the Ninja) at them to make them stuck in the Temple. Later, it's revealed that he tested the Ninja if they're worthy for the Airjitzu scroll. However, as the morning came and the curse on Yang's Temple started to take effect on the Ninja, Yang's other students showed themselves, revealing them to be chained up, as they were imprisoned by Yang. The Ninja then quickly fled to the entrance, not wanting to suffer the same fate as Yang's students. They manage to reach the entrance, but Cole dropped the scroll mid-way and thus had to go back in to retrieve it, which caused him to turn into a ghost, with Yang's laugh echoing from the Temple.
After his temple was torn out of Ninjago to help construct Djinjago, he left his temple to angrily confronted Nadakhan, claiming domain. However, the latter, unimpressed, promptly ordered Dogshank to shoot water at him and his students, forcing them to abandon the temple.
Yang's temple was strangely left still floating in the sky despite Jay's final wish. This may be due to Yang having "power" over his temple, being able to do many things with it.