Eh, not a fan of what Oda did with Pudding there. I guess it falls in line with the clues we were given with how she looked up to Lola, but still... Did we really need another emotionally abused woman in One Piece? Would have preferred to have been unrepentant til the end. And Sanji gets a win despite once again never changing or developing.
Somebody else already said it once, One Piece is a comedy series, the main characters will not have huge changes in their characters. They have to make decisions, deal with the consequences and change their opinions, but they will stay the same people. Oda builds his stories around new characters. Those change and have arcs, while the Strawhats stay the same, since they are already great people with some flaws. it's the reason, the series could stay relevant this long.
Sanji cavalier act is a double-edged sword. Sometimes it makes him look like an idiot. He doesn't hit a woman, let them act freely and his lust makes it even worst. But at heart he actually is very sensitive and has a good understanding of woman, which is overshadowed by his desires again. Sanji doesn't need to change, he only needs somebody, who can calm him down.
Pudding is shown to be acting a lot. Maybe even her evil side is just an unconscious act, too. She plays a monster, since she believes anybody things of her as a monster, so she has to be one, right? This breakdown came out of nowhere, but those happen very often this way. The question is, can Sanji pull her over or not.
The situation is similar to Hitchcock's "Bomb under the table" scenario, just reversed. We the audience now, that there is a sensitive side of Pudding. If Sanji could touch this side again, maybe she could have a true change of hearts. I bet, there will be a battle about Pudding's soul at the end.