Who is the devil's best advocate?

Update: Interesting guesses and many have different perceptions and would like to see all of them.
Update 2: Darwin said his book was only a theory and looking for more answers
Update 3: Some say ministers are and if you can tell me why maybe you get ten points.
Update 4: Maybe I know but I am never going to tell you.
Update 5: Here is a picture of an animal that is a devil and this does not hurt the real one...

https://animals.sandiegozoo.org/sites/default/files/2016-09/animals_hero_tasmaniandevil.jpg
3 answers 3