What is evil? How about evil is dragging a pregnant woman out in the middle of an empty field and shooting her in the back of the head. Courtesy of "Ordinary Men".
How about evil is Unit 731. Or Auschwitz. Or the Soviet Gulag.
How about evil is rounding up the resentful people in your community, convincing them to overthrow the successful farmers that held anything up in society simply because they happened to have more, rape them, then ship them off to Siberia to freeze to death, resulting in the starvation of 6,000,000 Ukrainians during the Soviet era due to a lack of competent farmers?
How about a killer watching two unarmed policemen begging for their lives while the man simply shoots them both in the head.
You may see these as extreme examples. Perhaps. But so quick we are to detach ourselves from things like Nazis or experiment camps. The truth is, the Nazis were human, and you happen to be a human.
See, I think you're confusing moral greys with moral subjectivity. Ironically, people who aren't moral objectivists tend to make morality seem more stagnant and unchanging than it really is in their arguments, as though moral objectivists believe that something is wrong all the time no matter what. I haven't heard a single moral objectivist make the claim that morals are always always always consistent and stagnant and unchanging. It's a strawman; good and evil are black and white but that doesn't mean they are stagnant, or aren't circumstantial. Just because good and evil exist doesn't mean good and evil aren't dependent on circumstance. Idk where anyone gets that idea from, and they confuse it with subjectivity.