The fight wouldn't make sense, in my opinion, since I can't think of a single major fight involving Luffy where he's gone as the superior opponent against the opposite. Which is what he will be as the Pirate King, since it symbolizes being above the Emperors & Admirals.
And Dragon would be a waste on Akainu, it's like when you're aiming at the final boss for your whole life, but end up having to only deal with one of the Boss's many subjects. Would just dehype Dragon if anything.
Sabo, seeing as Akainu and co are treating him a bigger deal than even the newly named emperor Luffy, makes the most sense. Due to there being political reasons for them to fight over, which should flesh out Sabo as a revolutionary if Oda decides to have the two fight over not just the Ace revenge factor (which alone is a pretty bad reason), but also for ideological differences that the two could bring up in their fight. He'd be a more meaningful fight for somebody as complex as Akainu, rather than the "every one of my friends should have meat!!!" guy.
Hmmm that could be a strong argument against Luffy vs Akainu , never thought of that before .
I guess you don't consider Luffy vs Hody and Luffy vs Caesar major fights then ? We know Luffy was far stronger than them coming to their arcs .
If you don't consider them as major fights , i guess it's because they were fodders ? ( not even F6/Vet lvl )
So if we were to pinpoint a fight where Luffy's opponent is strong enough , what about Luffy vs Cracker then ?
Cracker was a strong Commander of Big Mom and Luffy was arguably superior in my opinion ( KKG would definitely have busted him )
What about Luffy vs Doflamingo ? Luffy was arguably superior as well
But regardless of Luffy was superior or not , Luffy could ragdoll him in G4
I mean yeah Luffy could do that to even Kaido ( in Act 1 ) , but Kaido 1 shotted him right after
We know Doflamingo couldn't do that even to an injured Luffy with his trump card ( Awakening )
We know Kaido had trump cards that he didn't even use vs Luffy in Act 1 as well ( Hybrid form , Drunken modes + FS , and his strongest attack the Flame Dragon )
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As for Sabo :
As i said before i don't have any problem with him vs Akainu .
Though him taking on Akainu ..... while Kizaru and Ryokugyu are taken on by Zoro and Sanji ..... could look out of place i guess ?
But yeah Sabo will be a monster who will surpass Dragon ( a top 3 character power lvl wise IMO )
And he is in that ASL Trio with Luffy & Ace ( and Luffy has PK lvl potential or a bit more , Ace had PK lvl potential , so Sabo may have PK lvl potential himself )
So yeah Sabo vs Akainu is OK