Has anyone trained with or have an understanding of the system that was practiced by master Duan? It seems to contain elements of TCM and qigong
Yes I have heard his system is Wu Ji Qigong but i do not know anything about his system. If i recall correctly there are a few western students living in China who trained under him or maybe trained from his disciples (i dont remember which one it was).
Master Duan, may he Rest In Peace, was the son of the Royal Medicine Healer of the Emperor. I can not speak on precisely what he taught. However he was a great and genuine man, you may find a few remaining documentaries on him. He was the lineage holder for Wu Ji Qi Gong. To my knowledge he did not officially pass it to anyone. There is one man claiming, I would avoid him.