At an unknown point in time, he was among the students taken under Yang's teachings, with Yang becoming infamous for his strict methods on him. However, unbeknownst to the public, he was secretly trapped in his temple, and after his death, were converted alongside his fellow students and mentor into ghosts. Yang then enslaved his former students, making them mindless servants to his will.
As the morning came and the curse on Yang's Temple started to take effect on the Ninja, he showed himself, revealing the student to be chained up, as he was imprisoned by Yang. The Ninja then quickly fled to the entrance, not wanting to suffer the same fate as him and the other 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. Fortunately he escaped the temple before he can meet the same fate as the students.
After Yang's temple was torn out of Ninjago to help construct Djinjago, he and the others left Yang's temple while Yang angrily confronts Nadakhan, claiming domain. However, the latter, unimpressed, promptly ordered Dogshank to shoot water at the students, forcing them to abandon the temple.
With Cole restrained, Yang has his students watch him while he opens the Rift of Return. However, Cole attacked them and went after Yang. The students went outside to watch, and jumped through once the portal opened to become mortal again.
- 61. "Wishmasters"
- Chris appears alongside Martin as one of the Ghost students featured in the 70590 Airjitzu Battle Grounds set.
- Coincidentally, the two share the names of the Kratt Brothers.