Casio knew himself not to be a born killer. While his main personality occasionally demonstrated some brutality, for the most part, he was not a man with a psychologically deviant thirst for murder. So, from an objective point of view, practicing South Dipper Red Vulture Fist was not really a suitable match for him.
Even his compatibility might be much lower than that of Feng Liusi's.
However, Casio's murderous personality could play a vital role at this time. This personality, stripped out by his Demon Idol Secret Martial Art Mental Method, was associated with his Dark Biological Transformation. The creatures of darkness, needless to say, were evil spirits that nakedly considered humans as snack bread. Their feelings toward humans were not Killing Intent, but natural hunger.
This was an unconsciousness more horrific than that of a born killer. It was not derived from hatred or disgust, but utterly natural.
