According to resources, basically Mo Pai*, the art Mo Tzu passed on to Chang San Feng (Zhang Sanfeng), the founder of Tai Chi, is based on a hidden Chinese martial art. John Chang demonstrated some pyrokinesis and electrokinesis aspects of that art in Ring of Fire: https://youtu.be/TdYM0vNufwc?si=lE-VwKnwgAR4BwoR
*Mo Pai is a hidden school and meant to be a hidden school with a strong view of yuanfen. That is, your life path will either bring you to a Mo pai master or it will not. Kostas Danaos and Jim McMillian are two who we can verify became students of John Chang. Others I cannot confirm. The training can be dangerous without guidance of a master like John Chang. It was originally a killing art, not a healing art. It has focus on some deadly palm striking, built off of years of neigong training to develop a powerful internal force.

Chang San Feng is the legendary founder of Tai Chi and was early associated with Shaolin temple, and later created his art at Wu Dang temple. Sadly there is little to no evidence of his existence. His life is given in two different centuries and dynasty’s. One account places him in the Song dynasty, and the other the Yuan dynasty. There does exist from Wu Dang today several branches of Tai Chi including San Feng Pai. This is contested information with scholars.
Chang San Feng’s writings are obscure. It takes the Taoist philosophy and Neidan (alchemy) in a interesting direction for health, self defense, wisdom, and Immortality. It is said he recommended to seek using natural breathing to locate the immortal self. On the heart-mind, it is said, “When the humanly mind is removed, the heavenly mind resides”, and to “gently be aware of the breath until it becomes long, soft, and deep”. A note I found here from Luk Chan’s Taoist Yoga book, quotes Chang San Feng as saying, “Old people who are impotent may use artificial means to arouse the genital organ. After it is aroused, one should gather the generative force (jing), from the vitality (Qi) of the body. A man lives because of this vitality (Qi) which produce the generative force (Jing) and dies when exhausted.”
Stuart Olsen wrote about Chang San Feng and says, Chang San Feng liked to practice the sword in the moonlight to enliven his shen, Tai Chi in the dark to increase his jing, climb mountains to broaden his Qi, read and study to illuminate his mind, and to practice sitting neigong at the Zi time (midnight) to develop clarity to one’s true nature. It is also mentioned that xing gong, ming gong, and medicine, were the way to attain the Tao. Xing gong helped to awaken the spiritual nature, Ming gong nourished your life, and medicine harmonized the yin and yang of a person. Other parts of Stuart’s books said that Chang San feng’s basic idea was there is a difference between “Attaining” and “Realizing” the Tao. “Attained in Tao” meant the cultivator has found the correct path to Tao through virtues and merit practices. “Realizing Tao” however was the ability to transform into the immortal body with practices of merit and virtue. Some more notes from Stuart Olsen’s book has a prescription that Chang San Feng gave: try 15 minutes of sitting, 15 minutes of standing (zhan zhuang), repeat 15 minutes of sitting, 15 minutes of standing, then15 minutes of standing then finally walking. Long forceful meditations were not required, and to make any progress, you need to devote the first 18 days to dan tien training and getting rid of the extra thoughts in the mind just to prepare ‘the cauldron’ at lower dan tien (LDT). The next 100 days are devoted to jing and qi in the lower dan tien to form the pearl. Lastly, 9 additional months working on the Xiao Chou tien or “microcosmic orbit”.
Going through Mo’pai: Resources: found at bottom of page. (Kostas Danaos, Shifu Lin, James Van Gelder, James McMillian)
Some of the notes from Magus of Java says that Mo Tzu was a rival of Confucius and that his art had 72 levels that included a type of isometrics and contraction techniques, Yang energy (body metabolism and heat) cultivation, pranayama, kundalini and tantric attributes similar to tummo (inner heat method). Methods from Bodhidharma are mentioned including the 18 Arhat fist, Muscle and tendon change classic, the Marrow washing classic, and finally Chan (Zen) Dhyana (meditation). The book warns to be sure you are grounded with the earth in practice (sit or stand on earth or a grounding device) and that meditation needs to be taken seriously: 81 hours of pure meditation gathered over years. For example, if you sit for 20 minutes but only quieted the mind for 5 minutes, you only gained 5 minutes of true meditation, not 20 minutes. Meditation was a foundation along with abstinence from sex (wait 72 hours to resume training after sex) . All of these are key to developing the Yang Qi foundation.


Notes from Jeff McDuffie:
Various techniques researched and discussed with Jeff McDuffie. Based on “The Secrets of Internal Power”, that Jeff McDuffie found on a now deleted Chinese website, he says this is the core Mo pai method. Jeff mentions Fu Gong qi, the art of qi transference into another body to check progress and to increase a persons qi in the lower dan tien. Jeff mentions, “Leiyin palm or thunder palm is the biggest secret in secrets of internal power. Yin and yang channels merge. It is also called yin yang hand.” Jeff says, “the truth is that nobody will know about this book because the method is not found anywhere in China. It’s hard to track down the book that the ‘secrets of internal power’ comes from. I asked the guy before the site was deleted where those instructions are from, and he just said from an old book.” On a few occasions Jeff and I have used Chinese web browsers behind the ‘great fire wall of China’ and yes, as a former cyber security expert, sites within China do disappear or block access and maliciously attack your computer. One such site killed my WeChat account.

references and suggested readings:
suggested resources (No particular order):
The Magus of Java- Kosta Danaos
Enter Mo Pai- James Van Gelder
Nei Kung- Secret teachings of the Warrior Sages- Kostas Danaos
Beginning Mo Pai- Shifu Lin
Taoist Herbal Formulas- Shifu Lim
Level 2 Mo Pai- Shifu Lin
Secrets of Internal Power- Jeff McDuffie
Taijiquan Treatise attributed to the Sung Dynasty Doaist priest Zhang Sanfeng- Stuart Alve Olson
Other resources
Ring of Fire: https://youtu.be/TdYM0vNufwc?si=lE-VwKnwgAR4BwoR
Level 1-4: https://youtu.be/MP8XSwVfUPY?si=-BmfJQMt1nnI8ZND
Jim McMillian demo- https://youtu.be/aIByWxdtSow?si=-xMw7S5SzW1qh147
Nathan Brine Commentary on Mo Pai: https://youtu.be/snXtbm1VJE0?si=erxC7IcoJ14QvmDL
Mo Pai test level 2b: https://youtu.be/2vqaXq8P4vg?si=eIcVrFI1hdKO6JBL
Mo Pai test: https://youtu.be/G0tj_ZgwCsc?si=mIK9_Y0YUhZuWqyS
Kosta Danaos interview: https://www.youtube.com/live/cflTI6MzpPI?si=VeBj0GmiSeHkx6-b
second one: https://youtu.be/rJXOq185H64?si=PdqgKV5-j1Taph66
Jim Mcmillian interview: https://youtu.be/7yaPc2AbUbk?si=Nvlpc7esPyBr0hUI