The concept of “evil” is a human construct; as such, its entire existence is predicated upon human perspective and application. It does not exist without it. The various contexts and reasons for the label or its application are tightly coupled with concepts of societal and cultural preference, extending through the various belief systems and underlying themes, myths, or ideological truths that humans find meaningful.
“Evil” as a definition is ultimately a subjective, dualistic thing. For every individual who will label something “evil”, there is someone who will not. The vying over “who is correct, accurate, or right” is not an exercise in intellectual or logical effort as much as it is an exercise in social or cultural dominance, only slightly removed from the various other dominance behaviors found throughout the entirety of the Earth’s living systems.
The underlying assumption that there is a “good” which, when flouted, ignored, or deliberately impeded “is evil” is nothing more or less than another layer of competition amongst this particular pack of mammals; be it for personal satisfaction, superiority, or collective strength, power, or ascendancy within the context of human society and culture.
There is no separation of the concept or label from its creators, just as there is no existence of the concept or label without its creators.
Ergo, “evil” is humanity; humanity created it, perpetrates it, and, even in the act of attempting to agree upon what it means, ensures its continuance.