I think that Dragon will die to serve as a hype tool for Imu to hype him up even more. Sabo and the rest of the RA will fight Akainu and the Marines.
It has been built up that the Tenryuubito will be taken down by the D. Sure Dragon is a D, but Luffy is “the” D, so it makes sense that would be Luffy and his crew that take down the Tenryuubito
Honestly it seems like the CP-0 were created as a direct reason to face the Revolutionaries. Both groups literally have the opposite goals.
- CP-0: Protect and serve the Tenryuubito
- Revolutionaries: To take out the Tenryuubito
Pretty sure whoever leads CP-0 and his second in command will be Dragon and Sabo's main adversary in the final war. This is also why there are 4 additional commanders introduced on top of Ivankov, to assist with the number of CP-0 members that exist (so far there are 7 members not including Spandam; Lucci, Stussy, Kaku and 4 unknown masked men).
Akainu and his admirals are likely entirely reserved for Luffy and his top guys, there are are clear parallels/Relationships between them:
- Akainu: Luffy defeating him is actually important. Sabo has virtually nothing to do with Akainu. He wasn't there when Ace was killed. Its not THAT personal to him.
- Kizaru: Is the primary reason for why Arlong eventually turned on the Sun Pirates.
- Fujitora: A swordsman, and one that has encountered Zoro prior. His duty will cause him and Zoro to clash
- Ryokugyu: Doesn't eat or appreciate eating (directly the opposite of Sanji) and is also a ladies man. He also apparently made Fuji's food so its very possible he's also a cook.
I think the Marine higher ups, as well as the upper echelon of the WG (Im, Kong, Gorosei, etc) are all being reserved for Luffy's crew. The setup is honestly there for it.