There's no need to assume some kind of verbal semantics here. Honestly, if you describe anything with an adjective, it is always subjective without quantifying. That's part of the English language. That shouldn't prevent communication.
For example, if I say a cloth is wet, there are really varying degrees of moisture volume. What if you describe a woman as beautiful? Well, there are varying degrees of that, too.
And so it is for being evil. They can be evil by definition without being as offensive as a despot, and there is nothing about the English language that requires me to quantify.