Great fight chapter. Easily the best of the Tobi Roppo series.
Robin received more focus in this fight than she has in years. It honestly feels like pre-timeskip again. We get more callbacks towards Sanji asking for Robin's aid, and we see why what Sanji did meant a lot to her. He asked for her help. The girl who was a demon, who was avoided by everyone, not trusted by anyone, had people who needed her. That's what allowed to her to become a monster for them.
It's similar to Chopper, who stressed that he'll be a Monster for his friends. The ones who will always be by his side, no matter if he's one or not.
Oda took full advantage of the crew dynamics for this battle against Maria to be satisfying. It's the same formula as the Kalifa fight, but, thematically, it works so much more, as the Kalifa fight was more about introducing Sanji's weaknesses towards fighting women whilst it only played a component in the Maria scenario. It was more about reinforcing the reliance and trust the Straw Hats have for each other, especially if they are in a situation they can't handle on their own.
Lastly, Momo becoming an adult. I can't say I'm surprised by this, since it was something bound to be addressed (Why else have Shinobu, the one with the aging fruit, around Momo so much?" I'm very conflicted about this. This will depend heavily on the execution. It has the opportunity to be both a last minute solution with real consequences Momo will have to endure for years to come, or a horribly contrived plotpoint just for Oda to draw Luffy riding a giant dragon. I'll wait and see how it goes.
Either way, the arc is winding down, and things are only heating up. We're now down to the main executive battles, Linlin, and Kaido.