Akainu or Imu are billion times more likely to be the final villain than Blackbeard.
Blackbeard's crew is ass cheeks. His 2nd strongest is Shiryu, literally a former marine worker that is nowhere close in power to an Admiral. And his 3rd strongest? Literally no one knows who it even is, that's how ass his crew is.
Meanwhile Akainu has 3 Admirals working under him. One of Akainu's underlings can literally solo Blackbeard's crew and probably Blackbeard himself.
This alone proves that Blackbeard won't be the final villain and that Akainu will come later, since characters like Zoro and Sanji cannot decrease in strength in order to fight BB's crew after fighting the Admirals.
Whitebeard himself said that BB is not the one who will find One Piece, but the one that will, will challenge Marines and WG. Again, quite literally saying that BB will be nothing more than just a fight for Luffy before finding the one piece, and that WG/Marines are the final fight.
Blackbeard's crew is ass cheeks. His 2nd strongest is Shiryu, literally a former marine worker that is nowhere close in power to an Admiral. And his 3rd strongest? Literally no one knows who it even is, that's how ass his crew is.
Meanwhile Akainu has 3 Admirals working under him. One of Akainu's underlings can literally solo Blackbeard's crew and probably Blackbeard himself.
This alone proves that Blackbeard won't be the final villain and that Akainu will come later, since characters like Zoro and Sanji cannot decrease in strength in order to fight BB's crew after fighting the Admirals.
Whitebeard himself said that BB is not the one who will find One Piece, but the one that will, will challenge Marines and WG. Again, quite literally saying that BB will be nothing more than just a fight for Luffy before finding the one piece, and that WG/Marines are the final fight.