"One Piece" chapter 843 ended with Luffy and Nami finally getting into Big Mom's castle and reuniting with Sanji. However, Sanji refused to leave and simply stated that he wanted to marry Pudding and become a prince instead of returning to his life as a pirate. In chapter 844, this may cause Luffy and Sanji to fight each other head on.
Fans of the franchise will recall that Sanji is merely lying to Luffy because, the truth is, he doesn't want to endanger his master's life. Because of this, he is willing to do everything to convince Luffy and Nami to leave before the Vinsmoke family arrive.
According to Hall of Fame Magazine, Luffy is aware that there is something holding Sanji back, and he will not agree to just leave his friend and crew member without knowing what the truth really was. This is why Sanji and Luffy may end up fighting until Sanji gives in and tells Luffy everything so that they can work together and make a new plan.
The report also points out that the Vinsmoke family may be running late, presumably since a previous chapter revealed that they were already plotting of launching an ambush against Big Mom when they arrive for the wedding. Since Big Mom doesn't want to wait all day, she will get angry and leave her castle to look for them. This may be when they confront each other in all-out war.
Fans speculate that during the chaos of the fight between Big Mom and the Vinsmoke family, Luffy, Sanji, and Nami may be able to plan a way to escape. Chopper and Carrot are also expected to meet up with them soon, and they could all work out a way to get off Big Mom's castle before she or the Vinsmoke target them. They may also come up with a way to stop Sanji's father from killing Zeff.
