By 1935 Ng Wy Nung had been learning from Lau Fat Mon for over a decade. He had learned the deepest secrets of Eagle Claw including three master forms; Jui Lok Tong (drunken), Fuk Fu Kuen (control the tiger fist) and Lin Kuen (connecting fist- created by Chan Tzi Ching). He also learned the complete Wu Tai Chi Chuan System from Chiu Saw Chun and Ngau Yun Ho.

In 1942, Hong Kong was in bad shape from the Japanese invasion and World War II. Ng Wai Nung returned to his home village to teach. He became famous for the Kwan Do set Sei Moon Dai Do (Four Doors Great Knife). He returned to Hong Kong in 1949 where he taught for seven years. Among his advanced students was Leung Shum.