Is there an idiom which implies that the only match of a certain entity is another entity of the same kind, with some sort of 'sordidness' in the entities?
Paul is a seasoned bluffer. Ron can't handle him, only George can. Only diamond can cut diamond
Perversion here is Paul and George (implied) being bluffers.
I am NOT looking to use it in the following sense:
Paul is a good wrestler in 200kg category. Ron is a champion of 300kg category but he cannot handle him, only John can.
I'm looking for a replacement of 'only diamond can cut diamond' in the above sentence.
Perversion -> sordidness
phrase -> idiom
Also, I like @silenus's answer: "It takes a thief to catch a thief", its perfect based on my initial question but is there a idiom where the entity being used as a comparison doesn't imply any sordidness on its own? e.g. Diamond is neutral but thief, not so much.