I was incredibly astonished to hear that Omar had been defeated. He was definitely among the stronger of the Seven Original Sins. The undead knights I sent to assist him were courageous and skilled fighters. The Mountain Inferno, which was Pride's Circle of Hell, shouldn't have feared any large-scale group battle. It was inconceivable that Pride was the first to have been defeated.
Pride stemmed from "levels". At first, all humans were perhaps indeed equal. But as society developed, human habits developed to classify people into different social levels. Concepts like upper, middle, and low class appeared. Those who stood high above got accustomed to looking down at those below them, along with viewing the lower classes as not even human or toys.