I don’t normally go in for power scaling discussions but I have thought this question quite interesting. Is it possible for Kid and Law to defeat Big Mom? I’ve been thinking about it and I think it is possible for them to defeat a Yonko. Let me explain how I think it could go down.
First of all, the most obvious observation is that Kid uses the power of magnetism and that Napoleon is a metal sword. Already there is one way in which Kid could counter Big Mom. He can repel any attack from Napoleon.
Next, we have Hera, Big Mom’s replacement for Zeus. This homie may also be possible to counter through Kid’s power of magnetism. In theory, Kid can harness Hera’s electricity through electromagnetism. In theory, even without Devil Fruit Awakening and almost certainly if he does get that, Kid can use this electromagnetism in a sort of EMP attack.
If Kid is able to do this, then what if Law combines his Room and Counter Shock with it? In theory, this would make a huge electromagnetic chamber and if Yonko Big Mom is caught inside it, it could do serious damage.
That gives them a way to counter 2/3 of Big Mom’s main homies, the remaining problem is Prometheus. This I think will be the one that Law counters. We’ve already seen that Prometheus isn’t much use when split into parts. This could be achieved with Shambles.
If they can achieve these 3 things, then they will have effectively neutralized all of Big Mom’s homies and been able to use them against her to deal some damage. However, that’s not likely to be enough. Big Mom is not very vulnerable in her regular state.
Before we get to the solution to that problem, let’s address the external factor affecting the battle. Kid being tagged by Hawkin’s power. This is really down to Killer to solve but it will make the fight harder for Kid. That’s why it’s likely that Kid is the 1% man. In fact, on a recent cover page, Kid even has 99% written on his apron, not only that but birds are roosting on his head. “The birds coming home to roost”, often means the past coming back to bite you. In Kid’s case, his past with Big Mom and with Hawkins.
Putting all this together, it makes it highly likely that Kid will be having a near-death experience in this battle, and achieving all these things will not be so simple as I’ve made them seem. The crux of the battle will probably be Big Mom falling into a rage mode.
We know that when Big Mom is in her rage mode, her ‘iron balloon’ defense drops. This will likely be the key to defeating her. They’ll have a much better chance at it than Capone did.
Once Big Mom is in her rage mode, she also won’t be in control of her actions, this will make it very dangerous to fight her but significantly easier to damage her. This is likely where Kid would use Punk Rotten and Law would use Gamma Knife.
At this point, Big Mom’s homies will have been neutralized, she will have been somewhat hurt by her own powers, will have fallen into a rage mode, making her vulnerable & then she will have been hit with Kid and Law’s strongest attacks. This may well be the way she is defeated!