The Datsik album speaks of some kind of pure evil. I really don't think humans can embody pure evil. The resulting person would be alien to all other humans, and by this disconnect, would not be able to function in relation to others. Could they act destructively as a nuclear blast would? Sure, but they couldn't lead others, hold down a job, pay taxes, and so on. Either they would destruct as people, or be so disconnected that they would have to exist at another level.
My psychic experience confirms this. I've encountered things that approached a variation of pure evil. It was best not "look" or perceive these beings as they are alien to us humans. Contact would not benefit us, and I have to wonder if the beings would negatively impacted as well. The synthesis would be unlike either, kind of like water and fire mixing, creating steam. This is conjecture, but it feels right. Opinions anybody?
The really interesting thing about this is the flip side. If people cannot embody pure evil, I suspect that they could not embody pure good either. The same rulebook would apply. Hmm...
So we humans, in our mixed up combination of evil and good, think that the purities can be humanized in some way. Dastik has pure evil monsters on their albums and the newage community speaks of our moving to light bodies. Could we transition to pure states? Sure, but we probably wouldn't be human anymore, and we would leave the rest of humanity behind, separated by our purity.