User blog comment:Jrotc193/Final Matchup/@comment-2001:8003:100A:5100:38AB:67E4:C844:34F8-20200120024927/@comment-108.83.222.210-20200123195208

The fact that Blackbeard doesn't appear to be a final villain does not mean he will not end up that way. Putting aside everything else for a moment, he seems to have a habit of managing to surprise people who underestimate him. Luffy is the same, no one would have thought when he was introduced that he would be challenging the Yonko and yet here he is. Even after the time skip in places such as Dressrosa he proved contrary to people's perceptions of him in some ways. Aside from this, he is one of two people that Luffy will absolutely have to face at some point during or after his journey to become the pirate king and he has a very personal reason to want to defeat Blackbeard. Also the Blackbeard pirates are a dark mirror of the Strawhats in a sense, a foil in a manner of speaking. With all these facts my conclusion is that there are two people Luffy absolutely must defeat before the end of this and he will face them sooner or later. These people are Blackbeard and Akainu who is a foil in the sense of being an opposite to Luffy and likewise also has Luffy's anger for similar personal reasons. It is in my opinion, just a matter of which one stands at the end as the final boss for him to face. Luffy may well fight against Im, but he has always known what opponents he has to face and if this fight happens I expect that Akainu will want to fight Luffy just as badly as Luffy will want to fight him. I expect the world to change when the end of the series comes. What that change will entail and the precise details are yet to be explained.