Given the way Big Mom's being treated, I can't help wonder if it'll be Kaido they fight last, or Big Mom. They keep avoiding a fight with her by either running or removing her from the fight, so it really makes me think she might be fought after Kaido. Given what we've seen of her, it doesn't feel like they have much of a chance against her if she were actually fighting seriously and not just standing around dumbstruck at their actions or yelling at them. If they manage to beat Kaido, though, maybe they do.