So akainu --- BB ---- Imu in same arc? Nah not happening
And imu is the main bad to joyboy aka luffy
And imu is the main bad to joyboy aka luffy
Maybe Blackbeard falls before the Final War in Laugh Tale. Maybe Akainu does. Maybe the final war is a 3 part war where the Marines are fought at New Marineford, then Im is fought at Mariejois, followed by Blackbeard and/or Shanks at God Valley. Maybe it's a huge battle Royale in the endgame and Luffy has a 3 way fight with Im and Blackbeard.
We literally cannot assume the structure of the final battles yet when there is at least 1-2 more arcs before Laugh Tale and we have no idea if Laugh Tale itself will be long or short. Then we have no idea how big the Final War will be. Then we have no idea if something comes after as a closer (i.e. God Valley).
We simply do not know.