The name of very secret norwegian martial art. It is known within the martial arts community as the martial art with the best defense, and the most deadly attacks, in the world. It derives from the ancient martial art of JuJitsu and kung-fu.
"Oh noes! he has a black belt in Kjell-Fu! we are going to die!"
"Stop right there! I am a master of the ancient art of Kjell-Fu!"