I am starting to get anxiety about how careless Luffy is around water with his Devil Fruit curse to not be able to swim. We see him repeatedly running across some very thin wooden pier thing towards Krieg while Krieg shoots him with various projectiles, and Luffy is both taking hits & jumping around to dodge, which just seems reckless in numerous ways, but, of course, that is his Straw Hat style, and he proceeds to just punch Krieg right in the face through the spiked porcupine cape, leaving his hand bleeding & Krieg on the floor. This is precisely what Zeff means when he says Luffy will win because “he does know fear”: a positive attitude mixed with determined courage is more powerful than any other weapon.
The strength of confidence is a recurring theme in the show, and even just in this episode, we get a look at Krieg’s crew losing morale and confidence as the fight progresses. First, they see the way Krieg treats Gin, his longest & most loyal crewmember, with such disrespect, even noting that Krieg needlessly mocks the dying man, and start to realize how Krieg would treat them if they ever made any sort of mistake. Then they see Luffy punch him through the cape and start to realize that Krieg is not invincible but just a guy in a suit of armor; without the confidence that their leader is unstoppable, they are less & less likely to persevere, this being a direct foil to Luffy & crew relying on their neverending resilience & positivity. They even discuss how if Krieg loses to a “kid”, Krieg & his crew’s reputation will never recover, which again goes to show the value of word-of-mouth information in this post-apocalyptic island world, but also applies just to Krieg’s reputation amongst his own crew being tarnished to the point of a failure to continue operating as a cohesive pirate fleet.
Gin is an absolutely fascinating character and I empathize with the two chefs frantically trying to keep him alive near the end of the episode because I want to see more of this guy. He has clearly committed many dark, twisted, and decidedly evil tasks in his time as a pirate, but he still has a strong internal code of honor as well as the trust self-awareness to recognize his own flaws and to objectively see the perspective of others, notably when he agrees that Krieg should kill him for disobeying an order because he would do the same thing if he were captain and his crew followed their emotions instead of their captain’s orders. Not only that, Gin still seems to have a firm respect for his captain even as Krieg is trying to kill him. It seems to me that Sanji feeding him has made Gin realize that there are in fact good humans in the world, which could be shaking his whole worldview at this point if he has been doing these evil actions under the assumption that all people are bad and deserve violence against them in one way or another. Gin’s reflection on the fact that maybe at least some of the people he has killed over the years were also good people deserving of a better life is weighing on his shoulders, filling the pirate with regret and a final death wish to rid himself of suffering, hence disobeying Krieg and accepting his fatal punishment.
Last note, all of the sailors are very good at treading water. We see dozens of them, pirates & chefs alike, almost perfectly still as they float at the surface, far out in the water where the ocean floor must be a kilometer deep or more. As the battle approaches a climax, we even see them cheering in the air without losing any balance. This could simply be lazy animation but I believe it is somewhat intentional to show the high level of swimming ability these sailors hold, spending most of their lives on the sea. They are comfortable in water of any depth, and I think this also holds a mirror to Luffy’s inability to swim by comparing their lack of battle proficiency with Luffy’s; not everyone can do everything but everyone can do something.