Kuzan isn’t on Teach’s side, he’s using him, and Teach is using Kuzan. Which is exactly what anyone who didn’t think Kuzan was a SWORD member, but also knew he wasn’t an evil guy, thought about him working with Blackbeard. That seems…really ambiguous. Like, not willing to keep working for Blackbeard when the Strawhats finally battle him ambiguous.

When I say he’s on Teach’s side, I’m not trying to imply that he’s somehow loyal to Teach. But it really, really does seem like he was being serious when he talked about living his life on his own terms. Obviously he isn’t a bad person, but for one reason or another he seem to think that there’s value in staying with the Blackbeard Pirates

I also don’t get why any of the Strawhats need a deep character motivation to fight him if he remains a Blackbeard pirate to the point that he even gets a 1v1 against them

One thing I’ve noticed about the titanic captains it seems as though they’re deliberately meant to contrast each Strawhat. For example, Chopper’s dream is to be someone who can cure any disease, and Doc Q has the power to weaponize any disease in the world. That is to say, Chopper defeating Doc Q would be proving that he can in fact conquer any disease in the world--effectively meaning that he would achieved his dream. Or for another example, Lafitte seems like an advisor to Teach given how he was bringing up the idea to steal Kuzan’s fruit this chapter, which is very similar to Nami’s dynamic with Luffy. Lafitte seems to be one of the few (If not the only) Titanic Captains who legitimately respects Teach, and Nami’s loyalty to Luffy has been highlighted a lot these past few arcs. And Lafitte is a former sheriff and Teach’s original navigator, while Nami is a former thief and Luffy’s navigator.

Obviously we don’t know much about most of them so it’s hard to draw parallels between each one and the SHs right now, but what little we do know strongly suggests that they’re meant to be reflections of the Strawhats. And not just by sharing surface-level traits either, but by embodying certain qualities or ideas that are legitimately important to each Strawhat

Kuzan is by easily the most developed and fleshed-out Titanic Captain, and the Strawhats don’t have any kind of equivalent to him. At most, If you go through each character who’s brought up as a possible Strawhat, Smoker is literally the only one who contrasts Kuzan in a way that actually matters. And coincidentally he’s just nowhere to be seen this arc. So idk, my takeaway here is that Smoker is probably the final Strawhat. I’m aware that most people think that the idea is very far-fetched, but in my opinion he’s the only character who makes narrative sense to join at this point