You said that the definition of justice is that you get what you deserve.
You said nothing about crimes or any definition of crime.
I feel reasonably sure that if there had been some sort of international court in 1815 a case could have been made against Napoleon that was at least as good as the justice he administered.
There was no court to try him but in natural justice the amount of suffering Napoleon was prepared to inflict on other people more than justified what he got.
Susan