So your justice is that they get to do all that evil and just die and cease to exist.
I'm sorry, were you under the impression that Hitler had a nice life from his evil onwards?
Do you even know how he died and how he spend his final years?
Stalin wasn't much better. Completely paranoid and spend years in fear of being assassinated by the very people close to him.
They lived in isolation, afraid of the world and even their very own people.
Sure, theoretically it is possible to do evil and "get away with it". In reality, that rarely happens though.
Mostly people endure the consequences of their actions during their lifetimes. Be it by getting caught by authorities, by spending their lives in fear, by spending their lives on the run and / or in total isolation constantly having to watch their backs or fear the next beverage or meal is going to poison them,...
If you think a life of evil pays off, you should take a closer look at reality and actually see how such people have to live their lives.
Let's even go to "lesser" evils then the kinds of Hitler. Let's take a type of evil that is even somewhat romanticised in pop-culture: mafia dons.
You watch the godfather and alike and what do you see?
Mob bosses effing around, beautiful women at every finger, fancy cars, front row seats for any show etc.
Now look beyond the movie.
Count the number of mob guys that lived in freedom passed the age of 40. Either they are in jail or killed.
If neither, multiple hit attempts on their lives.
Constant running from the law.
Constant fear of some young ambitious mob guy coming after them to "take over".
Seeing your friends and loved ones go to jail or get hit.
Actually being the one who gets the order to murder your best friend.
These people did not live "happy lives". These guys by the age of 40 or beyond are all either broken, paranoid, dead or in jail.
Those that aren't and
actually get away with it are an extreme minority.
Meanwhile, in your theology, your god doesn't care at all. All these guys have to do is "repent" and "accept christ as their lord and savior" and POOF, eternal bliss and all sins "washed away".
Meanwhile, genuinely good people who weren't christians get the Hitler treatment.
"justice".
What a bad joke.
That is like atheist heaven.
Living and ending my life like Hitler or Stalin or most mob guys did... not exactly my idea of "heaven".