I learned zhineng qigong and teachers of it said that unlike other types of   zhineng qigong is an "open" system where you take qi from the universe into the body  and purify the body with it open the maridians   and go through "purification"  which its symptoms are  pains and injuries and emotions etc ...    while they say closed qigong systems  practice for years just to purify the body  and just when they are high level after years of training they open to the universe

and gave an examples of all sorts of bad stuff hapening to qigong practiconers from this closed systems  that suddenly connected to the universe and sense thier body was clear the moment they opened to the universe  they got very strong "purification"  process and this caused them harm even death (worst example given was someone the moment he opened got blood out  hes eyes and other stuff that caused him to die fast  )

my terminology is bad and so my knoledge on this spesific thing except what was said to students in zhineng qigong course  -        would like to hear peoples view on this matter and anything people can add about this topic  of "purification"