I see that you added Red Baron to the trope list for Wild Wild West (film). I've seen the movie - once - but I don't remember seeing Manfred Freiherr von Richthofen appear anywhere in it. Are you sure you have the right entry (especially considering that a person is not a trope)?
Remember, All The Tropes is not TV Tropes - we pay attention to dictionary definitions, and rename tropes that had esoteric names wherever necessary.
Red Baron is indeed a Trope. It's a nickname for a person so Badass and so feared that he has a nickname that sounds Badass. Richthofen is the Trope Namer for it. There is no page that details Richthofen himself that I am aware of.
There is a page on All The Tropes that details Richthofen - I added an "appearances in fiction" list to it a couple of years ago. That page is called Red Baron.
The trope that you just described is called Sobriquet, after the word in the dictionary that has that definition.
EDIT: Looks like we posted at the same time.