I´ll start from the end. That looks like a stab wound on her left thigh.
Pudding is a pure and self-less person, a good person, Luffy´s friend (who´s got an eye for hearts, which is an understatement) and one of his (new) motivational factors for taking action on the island.
To me, it´s quite unbelievable how many people still expect bad things from her like hurting others, especially after last chapter. But OK.
So, Bege was my first suspect. But he usually goes for the kill (despite failing against Pekoms) and his way of fighting as the "Firetank pirate" (guns, canons, cavalry) would not go unnoticed.
That´s why, from my perspective, his move (when it comes), is much more suited in a crowded tea party/wedding which he could quickly turn into a bloody mess with his power.
Then I suddenly remembered that a couple of chapters ago one of BM´s children was "playing" with knives.
Anana, the psycho-kid.
And it would kind of make sense. Reiju, who is one of the strongest characters on the island, is more likely to have her guard down against a child, not expecting to be stabbed, than suffering such a wound in actual combat. Plus the wound is in a place which a kid could reach, not to mention Reiju looks like a doll/action-figure, if the kid needed an excuse. Anyway, would love to see Sanji find Reiju first.
As for the chapter itself. I have imagined some crazy action sequences with Chopper taking care of business in Ant-Man-like fashion, utilizing all of his formes in unreadable combos (kung-fu uppercut into monster hammer, brain dodge of scythe then locking it into that Diesel guy etc.), but I´m also satisfied with him being the brain of the operation and the mighty Croc-slam. I admit I did not get the frog switch which confused me quite a bit.
The highlight of the chapter was Carrot the phenomenal, agilie and strong bunny-girl. Stone-throw (did I see that right? OMG), gymnastics, electro-shocks and super-speed. Love her.
I am giving props to BM for actually trying to do something by herself already, that was a pretty badass entry to the chamber. Now I want to see a Devil Fruit soul battle and how well Brook´s power matches hers. Although now I have this weird thought in my mind of Brook´s Soul showcase resulting in BM wanting Brook as her x-th husband who can actually "control" her to an extent through sheer awesomeness).
Anyway, Pedro participating in this mission after losing 50 years of his life the last time he was there, what a brave warrior. Looking forward to that showdown, I just hope we get to see it. But yeah, this is yet another reason why BM will go down or lose a large portion of her power/influence soon including the years she takes from people.
Vinsmoke men just being their usual assholes, but it´s good that we still don´t know what exactly they want to achieve here.
I really, really liked the chapter.