I believe Oda doesn’t bring Ryokugyu to Wano to have a big fight with Pirate side there. The Yonko should be the final boss in an arc. Having a big serious fight after the boss is not appropriate, unless a new arc starts.
– If fighting happens and Pirate side wins, it would destroy the (hype) build up for Ryokugyu all this time.
– If fighting happens and Ryokugyu wins, it is not logical since Pirate side is equal to 2 Yonkos and some commanders. I highly doubt an Admiral can beat 2 Yonkos.
So, if Ryokugyu is here not to fight, then to do what? It is an Admiral debut, he must do something important here. All other Admirals did something in their debuts. It made me remember Wano is still having some issues left:
1: Villagers and Pirates who ate failed Smile fruits. They still always laugh like madmen.
2: Food resource. As I remember only the capital has resource to celebrate party. Other regions are still barren.
3: Former subordinates of Kaido who ate “proper” Smile fruit. Their abominable hybrid state is not an ideal condition to live, I have to say.
If only we have a powerful character to resolve those issues. That person must have the ability to “absorb” Smile fruits from people (and transfer to somewhere else). That person also must have the ability to grow plants on barren place, using nutrition elsewhere… If only… wait, we have that person! Guess who? The new powerful Admiral! Splendid! This would also be the perfect place for a debut Admiral to show off his powerful ability.
I guess Ryokugyu will still be pursuing our Pirates, but somehow our side will recognize the Admiral’s good actions, so they will flee instead of confronting the Admiral.
Theory by Trung-Hieu Ho (https://www.reddit.com/user/piouscity)