Every 50 years a cat demon has to be killed by a Cheung family member until the body-hopping feline demon's 9 lives are up. This time it falls on the shoulders of Master Cheung. He is afraid of cancer killing him before he can stop the demonic force, so when Long comes to him after his boss gets possessed, he tries teaching him his family's Mao Shan magic hoping to pass it onto him since Cheung's bloodline stops with himself.
The age of the demons has begun. Dr Faust has foreseen this rise of evil. Unfortunately, he is near death and is unable to personally battle this upcoming threat. Faust entrusts a young boy, Shingo Yamada, to take the responsibility of ridding the Earth of this new evil presence. Faust finds a birthmark on Shingo's forehead that signifies that he is the chosen demon fighter. Faust summons from hell what may be humanity's only hope of surviving: a less than enthusiastic devil named Mephisto rises. After signing a pact in blood to save humankind, Shingo and Mephisto set out to battle the supernatural world.
