A few words about my thoughts regarding Big Mom at the end of this arc (or beyond).
Though Big Mom was of course really introduced in this arc, in a way we were already introduced to her long ago. And not just in a "her-name-or-status-was-mentioned-way", but a very personal relationship was already set up. Even though we didn't know at the time that it was her. I mean the scene with Lola at the end of Thriller Bark, where Nami also gets the Vivre Card.
Here is cnet's translations of Lola's words (Chapter 489): > Lola: It's quite convenient! Here, I'll just sign this piece of my Mama's Vivre Card for you… / If you ever run into any troubles, you just follow this and ask my Mama to help you out, okay? // And tell her that I'm okay, while you're at it!
This first mentioning of her mother is very pleasant. It also specifically mentions that the crew would get help from Big Mom. Consider also that Lola is a trustworthy character and very likeable, basically a staunch ally of the Straw Hat crew at the time when she says this. The reader also has from this point on always the expectation at the back of his mind that whoever Lola's mother is, she will turn out to be really helpful. So before we even know the identity of Lola's mother, we are already prepared for her being a helpful character.
Since these words were spoken by a character who is treated in the story as a sympathetic ally, I still have a hard time believing we won't get exactly what was promised back in Thriller Bark and that Oda would change this very special expectation the reader has had for Lola's mother since Thriller Bark.
Now this chapter (859) basically confirms the theory that Pudding plays some kind of Evil Mastermind and has been manipulating especially Linlin's memories. So we now have a good reason to assume that at least the issue of Mom's hatred for Lola and her abusive behavior are really based on false memories. When her memories are finally restored (Pudding hopefully will be forced to repair this … :getlost:) we can assume that she will be quite fond of Lola and not such a bad person.
Except that her having good memories of Lola and her turning out to be not that bad or someone with whom some kind of truce can be negotiated isn't sufficient to end her role. Not after this introduction/first mentioning on Thriller Bark which is now a part of the series for almost half its length and which specifically points to her giving help to the Straw Hat Pirates.
This is similiar to the introduction of Kaido. We learned that Kaido wants to die (a spectacular death) and in a Manga where almost no one dies this is a very big hint that Kaido will die. Kaido's death wish and the fact that various kinds of punishments weren't enough to kill him are part of his introduction and thus part of his whole character arc. His character arc really cannot be completed without him dying. And since Big Mom was first introduced as Lola's Mom and her helping out was part of her description, I don't think her character arc can be completed without her in fact helping Luffy.
The way in which this was specifically alluded to sounds to me like we should expect something special of her. A "truce" or her not bothering the Straw Hats might not be enough to qualify as helping.
The question now becomes: How will she help the Straw Hats out? Could it be that she will be around after this arc and her being an ally will come into play later in the story, for instance after Wano?
If I misread things, feel free to correct me. But for example Greg's last comments seemed to imply that what we could expect from her is simply that she wouldn't turn out to be such an evil person. Like I said, I don't know if this fulfills the expectation of her helping out, which was specifically mentioned when Lola talked about her.