1- Marco vs King
I honestly don’t know what Oda is going to do with Marco, but as long as Marco is here he has to fight King. King is likely a Bird of some sort, I’m guessing Garuda since Garuda is intertwined with the concept of a Phoenix . And that is how King will become a problem for Marco.
King has large wings that enhances his fighting style and a bird zoan devil fruit. King’s pteranodon form vs Marco’s phoenix form makes totally sense. Also they both have flame powers. King is the perfect fight for Marco because he is the strongest opponent in Wano after the 2 Yonkos.
2- Sanji vs Queen
I think Sanji’s endgame fight is with Queen honestly, Chopper will try to fight Queen and ultimately lose, Queen will make a remark about making Chopper his test subject for an experiment. Right when Chopper is about to be attacked by Queen, Sanji will save him in anger.
In a similar manner he did with Usopp in Enies Lobby. Why is Sanji likely gonna fight Queen? It’s a long list but to name a few….
1. Queen sent the Tobiroppo after Sanji in the beginning of the arc.
2. Queen fits the quirky nature of Sanjis opponents.
3. Queen showed interest in Sanji because he’s a Vinsmoke and Judge’s son.
4. There’s a lot of Enies Lobby references going on for Sanji in this arc, aside from Black Maria/Khalifa there’s also Queen/Jabra.
Queen has a thick, queue-like braid through eight ties, with a stinger-shaped ending tuft, comes out the back of his head, which is otherwise bald. Additionally, he dons a Fu Manchu mustache whose tendrils widen as they droop to his chest.
Jabra has a Fu Manchu mustache, a pointed goatee, and long hair braided in a thick queue, that somewhat resembles a scorpion’s tail.
Like Jabra, Queen also likes to banter with the person right above him, but ultimately the key to this Sanji vs Queen matchup is the Judge connection.
3- Chopper, Carrot and maybe Wanda vs Perospero
No I don’t think Perospero is going to get the upper hand on Marco somehow because Carrot and Wanda will stop him before he gets the chance, Chopper after being saved by Sanji will see them struggling and go help them.
All 3 of these characters have been defeated and made fun of by Perospero at some point, and Chopper has connections to both Carrot and Wanda but especially Carrot.
4- Inuarashi and Nekomamushi vs Jack
I think Nekomamushi is going to come back and save Inuarashi unexpectedly from Hybrid form Jack. I think the point of Oda having Nekomamushi leave before is just to use Inuarashi to hype Jack’s Hybrid Form up a bit. The 2 of them will fight Hybrid Jack and ultimately 2 people will die in this fight, Jack being one of them. The one who survives will tell the tale to future generations.
5- Denjiro and Franky vs Sasaki
Sasaki wanted revenge against Denjiro for betraying him. Now that the Scabbards are running around the floors it makes it all the more likely that Denjiro and Sasaki will interact again. He will assist Franky in his fight. Finishing blow by Franky of course.
6- Jinbe and Kawamatsu vs Who’s Who
Kawamatsu being a fish-man does hint at him and Jinbe interacting at some point. It seemed he faced some racism in his earlier years that he and Jinbe could relate to. This would be a Sanji/Jinbe vs Wadutsumi situation where the characters don’t need each other to defeat their opponent, but rather Oda just wanting to show their abilities together. Finishing blow by Jinbe of course.
7- Nami, Usopp, Izo and Kiku vs Page One and Ulti
This sounds like a lot of people but it makes sense when you consider Ulti alone without Page One’s help almost defeated both Usopp and Nami. Like Page One and Ulti, Izo and Kiku are related. Izo is also a marksman like Usopp, he could potentially teach Usopp a few things about that and even show Usopp how marksmen utilize Observation Haki. Finishing Blow going to Nami and Usopp of course.
8- Robin and Brook vs Black Maria
This is one of the few matchups that’s actually already set, and it makes sense given it had almost 10 chapters of buildup. Brook said himself it seems like a good matchup. Of course it won’t be an easy fight at all for Robin and Brook.
9- Kinemon vs Kanjuro
This may be coming up very soon. Both Kinemon and Kanjuro will die in this fight. Kanjuro will try an underhanded tactic that will kill Kinemon. In the end, but Kinemon will ultimately get the final blow but die shortly afterwards. Yamato, Shinobu, Momonosuke and “potentially” Sanji will witness Kinemon’s final moments.