FACT: Evil cannot be justified using logic.

"Evil cannot be justified using logic."

... but it can be justified by some other means? What is your angle?

I thought this was already proved in the Star Trek episode Mirror, Mirror.

OK. I'll give it a shot.

"Good," being all good and nice and stuff, cannot exist without evil. Without evil, there are no parameters with which to describe good. Evil is justified for without it there is no good.

A hogwash justification but I used "logic" which you called for. So there it is.

The only logic that can be used to justify evil, is the flawed logic in the mind of the person (or more) who is doing the evil. Sound logic defeats the debate on evil deeds every time. I think Machiavelli's "The Prince" talks about the flawed logic that evil people use, particularly the phrase "The ends justify the means."

if the reward (say, for crime) vastly outweighs either the risk of punishment or the penalty, one might determine to commit a crime. to the extent that crime injures or harms individuals or groups or the society at large, this would constitute, objectively, an evil.

if the reward is great and the evil is small, one might determine to commit a small evil. one might, as well, resolve to use some of the reward to effect good in greater measure than the perceived evil (e.g. robin hood)

it's basically a utilitarian argument, but the argument against it is also rule utilitarian, or similarly invokes Kant's categorical imperative. but everyone will presumably not be in our position, or have our opportunity, so the categorical imperative doesn't really closely apply.

not the greatest argument, but i think it tracks pragmatic everyday thinking.

9/11 was an evil act that was justified as necessary for the Zionists to start war in the middle east.

It was logical for them, like sacrificing pawns to move the big players forward.

Killing someone in self defense or to protect others is sometimes seen as, "a necessary evil". To act contrarily to the instinct of self preservation would be illogical.

Flat Earthers and Trumpmagats attempt logic all the time. They are evil. Doesn't mean it is good logic.