Killah Black was not a concept put forth by mobb deep and the wu tang clan, he was actually a real person. Killah Black was Havoc's older brother who supposedly was a gangster he died in the late 90's in a car crash. Supposedly Havoc could go all over queens without getting robbed or touched when Killah black was alive. The Wu Tang Clan had associated who were rappers called Killa Bees which were there associates.
"U know who killah black is?"
"Yeah isn't he Havoc's gangster brother in QB who died in a car crash"