There's a small area I'd like to discuss.

We've known that Big Mom and Kaido are a couple of the strongest beings alive. And we've known and speculated that Shanks holds his spot an emperor not with strength, but with Haki. Due to several bits lately, I'd say we're being set up to accept Luffy as an emperor level character by the end of Wano.

Luffy was 'named' another emperor.

We saw Luffy try to fight Big Mom and get shut down.

We saw Luffy try to fight Kaido and get wrecked.

(these reinforced our overall view luffy vs their strengths)

We see Luffy put into another corner(prison), setting up his next hurdle to overcome/opportunity to power up.

Then we saw Luffy recall being shown by Rayleigh an 'armor' of Haki.

I'd say it's decently clear that Luffy is about to get a handle of this armor Haki that Rayleigh used. He's then going to fight with Kaido and/or BM to show the audience that he can no longer be taken down by an emperor level opponent.

While I like my own personal theory that Shanks' crew is actually a lot of devil fruit users, and Shanks' mode of operation is information warfare, I'm willing to concede that their style and method may simply be peak Haki, and that Haki alone was how Shanks was able to hold off Kaido.

TLDR: Luffy saves himself with super haki skillz. Gets recognized as an emperor at end of Wano.