We all know Marvel keeps denying that Namor will make his Marvel Cinematic Universe debut anytime soon but we also know Marvel isn't going to reveal any slight details if they were planning on introducing him.
If it happens or if it doesn't happen, we all know if Namor does make his way into the MCU, there's always been a beef between him and Black Panther. It would only make sense that if Namor is introduced, it's going to be done through a Black Panther movie.
So with that said, that brings in a book that everyone should own which is marked as the first battle between the two. That book is Defenders #84 which is still a very affordable book and the story within could also be copied or used for any future movie to get these two going at it before they settle their differences.
This is one of those small gamble spec worthy books. Even if this never happens, this is a great bronze age book that belongs in any good collection.
This might of been mentioned on other sites, if so, here's your due credit where applicable as this book came across my path while browsing eBay auctions.