catarina was recently revealed to have eaten the mythical nine tailed kitsune (kyuubi fruit )
sanji was originally going to be named naruto but naruto in the manga naruto had the nine tailed fox sealed inside him
oda and the writer of naruto are friends and oda had done shoutouts to naruto before with raizo along with this
so it would be a fitting reference for sanji to beat catarina devon
and for why sanji would break his code of not hitting a woman
catarina devon hunts for women she finds beautiful and decapitates their heads to add them to her personal collection she declares this a pursuit of beauty
and nami is a very beautiful woman
so sanji will break his rule for namis sake which is fitting for the first time sanji showed he had this rule nami confronted him on it and had to fight kalifa in her place.
and nine tails fox are tricksters who one of their abilities allow them to take human form typically beautiful women . and catarinas kyuubi powers allows her to cast illusions which reminds me of what mr.2 can do and mr.2 performed a trick in his fight against sanji where he turned into nami repeatedly to avoid getting hit but he had to turn back when he attacked because he needed to use the body he trained in. however catarina devon with her illusions could take the form of a nami and attack and in order to protect nami sanji will have to over come that and be willing to strike someone with namis visage.
Sanji has been pushed to his limits against female enemies before, foreshadowing that breaking his gentleman's code will be an inevitability. But what kind of woman would push Sanji past his breaking point? Why, a woman who seeks to harm the lovely ladies that Sanji fights to protect.
The Blackbeard pirates are set up to be the evil counterpart to the Straw Hats and it's almost certain that they'll face each other. Catarina Devon is a woman who is very ugly and was sent to Impel Down in the first place for decapitating beautiful women and collecting their heads. Considering how beautiful Nami and Robin and treated in-universe, there's no doubt she'll seek one of them for her collection. Though this could mean that either one of them will be her opponent. But I think the prospect of Sanji facing her would be more interesting, because her actions would definitely disgust Sanji from the bottom of his heart. Sanji will either finally be able to overcome his rule due to sheer anger, or
Sanji will be able to defeat a female antagonist due to Ivan changing her into a man
After two hellish years with the okamas, Sanji appears to have gained genuine respect for Ivan and have become friends and allies. Ivan will ultimately save his ass when Sanji has no choice but to fight a woman, by and transforming her into a man, with Sanji now free to give a huge ass-whooping to his newly-masculine enemy.
I doubt the Naruto connection. Oda also intended to break this connection by giving Sanji a new name.
I would still put my bets on either Vasco Shot or Avalo Pizarro. Vasco Shot as heavy Drinker could be the cook of the BBP and Avalo Pizarro is a royal from North Blue, thus both have a potential connection to Sanji.
There's definitely a lot more breadcrumbs that I thought based on the title, so thanks for sharing!
Oda also intended to break this connection by giving Sanji a new name.
To give further context, Oda, Kishimoto, and Kubo all started as rivals trying to fight against each other. Oda was mad that Naruto and Bleach were more popular than One Piece overseas while Kishimoto and Kubo were mad at how much of a monopoly Oda had on Japan. Oda and Kishimoto became quite close after being able to meet in person (I think it was WSJ required events). So Oda going out of his way to celebrate the ending of Naruto is significant. Oda creating a Kyuubi ability is significant, but can be downplayed since it is a common Japanese theme.
The most important part of the theory for me is the explanation of Sanji making an exception to his rule. I have zero hesitancy that Sanji would be able to kick Big Mom if Nami or Robin was in danger. I didn't know about the details of Catarina, so Catarina going after Nami and Sanji stepping in does fit all of their personalities. It is a great "maturation" process where Sanji is going to progress from what happened with Califa and what I see has a high percentage of occurring with Sanji.
I don't want to see Nami only fighting females, so I'm all for her matching up with a different Blackbeard exec and Sanji taking on Catarina.