You know, my first reaction was to : and say Chthon wins. But Chthon hasn't really gone up against other Gods/Cosmics (well except Demogorge but that was in their first encounter and he cut and ran) and Stranger had problems with the freakin' X-men, Pluto, the Silver Surfer, etc..!
So based on hyperbole and the Darkhold, I'm gonna go with Chthon for the majority.