"nasi pari o diavelos" is a Greek phrase that translates to "the devil takes care of his own." It is a proverb that is used to describe situations in which people who are doing something wrong or unethical seem to be protected or have good luck, as if the devil is watching over them and ensuring that they are not punished.
The phrase is often used in a humorous way, but it can also be used to express frustration or exasperation with someone who seems to be getting away with something unfair.