Killing intent was a special form of cultivation. It was very niche and deemed not very useful by most. It is plausible that most people in the Western Region have never heard of it. They might have a word of it written in their records, but who would read it? Who would care?
The effect of killing intent is physiological. If one is to face off against an opponent releasing their cultivated killing intent, one would feel uncomfortable? Uneasy? It is hard to describe.
The predominant feeling one gets is a sense of fear and intimidation. They lose control of themselves and their focus. Their will to fight collapses, and it is common for others to run away in face of one's killing intent or bow down in worship. In cases where the cultivation gap is large enough, someone can die from facing someone's killing intent.
