"One Piece" chapter 842 saw Luffy finally defeat Cracker, with the help of Nami, when he figured to devour all of the biscuit soldiers instead of trying to fight them. Luffy and the rest of his crew may now move forward to rescue their crewmember, Sanji, from Big Mom and the Vinsmoke family in chapter 843. This will officially end the "Totto Land" story arc as well.
According to Vine Report, Sanji is still in captivity at Whole Cake Island, and he is set to marry one of Big Mom's daughters. This would unite Big Mom's crew with the Vinsmoke family. However, the Vinsmokes are coming to the wedding to take down Big Mom, and a big war is will possibly erupt soon. During all this chaos, Luffy and his crew might step in to sneak Sanji away.
It is also pointed out that Carrot and Chopper are still stuck in the Mirror World. When they finally manage to break out, they are expected to meet up with Luffy and Nami somewhere inside Big Mom's castle, and they might be working together to break Sanji out or, at least, help Sanji defeat Big Mom and the Vinsmoke family.
One popular theory is that the Vinsmokes might switch sides and team up with Luffy in order to take down Big Mom. This comes after the fact that Big Mom is aiming to liquidate all their resources and essentially eliminate them. This may be the catalyst for Sanji to forgive his family and reconnect with the rest of the Vinsmoke despite their past transgressions against him.
Chatt Sports Net also points out that Sanji may fall in love with Lady Pudding, and this may throw a wrench in Luffy's plans to break him out or the Vinsmoke's plans of waging war against Big Mom.
