We finally get the insight into why Klahadore is so dead-set on not only stealing Kaya’s fortune but doing so legally and without suspicion. It is almost sad, to be honest, that he wants nothing more than a quiet happy peaceful life among these island villagers yet believes that the only way to obtain this is to murder a young woman in cold blood. We can only assume that Klahadore has experienced extreme trauma in his youth which inevitably shook & damaged his entire worldview into a place of extreme violence & isolation. It is pretty clear that Klahadore had already gained the trust of the family & and the island and could have genuinely enjoyed a peaceful life without this murderous plot, which I think is true irony that the failure of his plan is what will take away the possibility of which he dreams so much.
We also gain some insight into the politics of the Black Cat pirate crew, which, to be fair, resembles the sort of generic trope we are often served of pirates or other villains or even tribes without ill intent. Similar to the Sith in Star Wars, or the Wakandans in Black Panther, there is an element of ”might is right” for leadership in which the leader can be justly overthrown by being defeated in combat. In Black Panther, the tribes all join in combat to determine the leader of the country. In Star Wars, the Sith lords follow a ”rule of two” in which there is 1 master and 1 student and when the student is powerful enough to kill their master, they do so and become the new master. In One Piece, for this pirate crew at least, like in many other pirate medias, we see that the Meowban brothers are dissatisfied with the leadership of Captain Kuro and challenge him to a battle so that they can become the new captains of their crew.
It has been 3 years since Captain Kuro was with his crew, and during this time, Jango served as a sort of substitute captain of sorts, but it is clear that he is still subservient to Kuro & that the crew still sees Kuro as their rightful captain. What is noteworthy to me is that, if the crew as a whole felt that Kuro no longer deserved his station as captain, they could have sailed wherever they wanted to and simply not responded to the call to come to this island to help their captain with his plot to murder Kaya. However, these inner politics of the crew demand that they continue to follow Captain Kuro until either he dies or they stage a successful mutiny against him. Even a pirate has certain codes and creeds they follow, and these types of details helps the One Piece world feel more complete and filled in without unexplained background details.
Last note, I find it somewhat humorous that the crew, upon seeing Kaya, wants to just kill here then and there, more or less oblivious to the actual intent & mission their captain has set out to fulfill. All they know is that she is the woman they are supposed to kill, but they cannot keep straight why & how or the big picture at all. It is also clear that Jango is not much of a side-kick, either, as he was supposed to hypnotize Kaya to sign her will before the pirates made her death appear accidental, and they all just sort of blundered the entire operation because of mostly Zoro, one guy. I honestly think Captain Kuro is right to rid himself of this somewhat incompetent crew, he almost certainly would be more successful on his own, but perhaps that is another glimpse into his true desires for connection.