Baron Zemo
Both are major adversaries of Captain America and the Avengers and have led the Masters of Evil; the term also refers to a fictional barony that has spanned multiple decades of the fictional history of the Marvel Universe . 
<triplet> Captain America <subj> Avengers <obj> member of <subj> Marvel Universe <obj> from narrative universe <triplet> Avengers <subj> Captain America <obj> has part <triplet> Masters of Evil <subj> Marvel Universe <obj> from narrative universe