Full summary, thanks to redon from MangaHelpers Forum.
Chapter 1,038: “Kid & Law vs. Big Mom”.
Germa 66's Ahh… Emotionless Excursion, Vol. 3: “Niji and Yonji captured in Cocoa Island's Chocolat Town”. In the cover we see that Niji and Yonji are captured in one of Mont d'Or books (one of those books where Big Mom keeps her strange creatures). The book is in Chocolat Town's square, Oven is sitting in front of the book while people are looking at it. We also see that Pudding is looking at the book, she looks worried.
Chapter starts on the 3rd floor of Onigashima's castle that is completely on fire. Fukurokuju has started to burn but Raizou is covered in flames. However, both of them refused to release the other from their Jutsu. Fukurokuju tells Raizou again to release the Jutsu or they will both die, but Raizou doesn't answer him and puts up with the pain of the burns without losing concentration.
Cut to the 2nd floor of Onigashima's castle, samurai are trapped by fire and cannot escape. Suddenly, the rooftop collapses and nearly crushes the samurai, but Jinbe appears and manages to hold it up.
Jinbe: "Run away as soon as possible!!!
Hah... Hah...!! How the fire have spread so quickly!?
You must help you unconscious companions to escape!!
If you don't do it, a lot of them will die!!!"
Cut to the Live Floor, samurai run away from the explosions that take place in the area where Big Mom is fighting. Chopper, who is watching what's happening with Miyagi and Tristan, feels that something strange is happening to his body. Then his body returns to its normal form.
Chopper: "Hah... Hah...
I'm finally back to my normal form!!
But now there is something more important...!!
Miyagi!! I'm worried about Zoro!!"
Miyagi: "Yes... For the “medicine”."
Chopper: "The medicine gave Zoro “super recovery”...!!
But he will also sustain “twice” the damage in exchange right...!?
Zoro was already so injured he couldn't move.
If “twice” the damage is added to that...!!!
Cut now to outside of the castle. Zoro is conscious but someone has appeared in front of him.
Zoro: "Hah, hah...
Who are you.
...!! What is this.
I can't move...!!
Stop, stop!!!"
Someone dressed with a hood and carrying a huge scythe appeared in front of Zoro. That creature is surrounded by a very strange aura. In a closer shot, we can see that the creature is a skeleton that is about to attack Zoro with the scythe.
Cut to the right tower of Onigashima's Dome (in an area very close to where Zoro is). Franky is defeating the enemies that he finds in his path while he looks for Zoro. Franky wonders how far King sent Zoro with his attack.
Cut to the crawlspace of the 1st floor, where all Kaidou's subordinates who faced Izou have been defeated. Cut now to the 1st floor of castle's basement, where Izou lands (he jumped from the upper floors). We see Izou has a wound on his abdomen that is bleeding.
Suddenly, Izou turns around and points his gun at someone. We see that they are the two CP0 agents.
Izou: "Cipher Pol...!!"
CP0's boss: "... Well, it's actually Aigis “0”.
Izou... I am going to pretend I didn't see you.
From a certain point of view...
I would commit a great mistake if I let that the remnants of Shirohige Pirates escape...
Izu: "..."
CP0 boss: "But now we have to focus on the Straw Hat Pirates...
... I'll see you later..."
Izou is in silent for a few seconds, but finally raises one of his guns.
Izou: "No... Wait...
“CP0”."
Cut to the basement armory, Yamato is going down the last stairs.
Yamato: "I will arrive on time!!
I will arrive on time!!
Hah.
Hah."
However, when Yamato reaches the area where the giant explosives are, he sees Kazenbou has also arrived and that it's about to touch the bombs. Yamato acts quickly.
Yamato: "No, no!!!
Stop please!!
“Namuji Hyouga” (Namuji Glacier Fang)!!!"
Yamato freezes the bombs, becouse if such an amount of gunpowder explodes, everything will be over. However, Kazenbou touches the bombs and begins to thaw the ice. Yamato attacks Kazenbou.
Yamato: "Don't touch the gunpowder!!!
“Mahoroba” (Horse Illusion Blade - 馬幻刃 (まほろば))!!!"
Yamato hits Kazenbou with his kanabo and manages to attract its attention. Kazenbou takes out a hand from its body and attacks Yamato with a flame.
Kazenbou: "Ooooooh.
Orochi-sama...!!"
Yamato: "A hand!?
Woaaaah!!!"
Back to the Live Floor, we see Big Mom is attacking Law and Kid over and over again. Law and Kid's subordinates ask Big Mom to stop. Big Mom finally stops and stands in front of Law and Kid, who are heavily injured lying on the ground.
Big Mom: "Hah... Hah...
Hmm!! I feel sympathy for your subordinates..."
Heart Pirates: "Captain!!"
Big Mom: "Don't get up again!!
Ma~~~mamamama, haha...!!"
Law and Kid are completely defeated, Kid even has his eyes rolled back. Big Mom looks tired but without any major injuries. Law and Kid crews try to help their captains.
Kid Pirates: "Boss!!!
Be careful!! Is he still breathing!?"
Heart Pirates: "Medical team!!
We have to help captain!!!"
Big Mom attacks both crews before they can reach their captains.
Big Mom: "Sorry~~~!!
The battlefield cannot be filled with garbage!!!
“Tenman Daijizai Tenjin” (God of Lightning Tenjin)!!!"
Kid Pirates/Heart Pirates: "Uwaaaa!!!"
Big Mom looks up at the rooftop and says that looks like Kaidou's battle with the Straw Hat is not over yet.
Big Mom: "Hera!! Let's go to the rooftop!!
I'm a little tired.
So let's end this once and for all!!!"
Suddenly, Law gets up and prepares to attack Big Mom again.
Law: "“K ROOM”
Hah... Hah...
“ANAESTHESIA”
Prepared!!!"
Law pierces Big Mom's right arm and part of her face with the sword (sword goes in under Big Mom's mouth and goes out through Big Mom's left cheek). Everyone who sees the attack is shocked.
Kaidou's subordinates: "Uooh!!!
Big Mom is dead~~~!!!"
Homies: "Mamaaaa!!"
Chopper: "Torao!!
What is that sword!!"
Law: "Hah... Hah... LAST attack should have worked.
There's no damage when I pierce you... but..."
Big Mom: "Stop...!!!"
Law: "“Shock Wille”!!!"
Big Mom: "Bueh~~~!!!"
A powerful “shock wave” hits Big Mom inside her body, she bleeds from her mouth. Big Mom falls to the ground, iron Homies try to attack Law.
Homies: "What have you done to Mama~~~!!
Huh? What's happening!?
Something is pushing us...!!"
Kid attracts all metal objects in the area into his body, including the iron Homies.
Kid: "All metal objects,
follow my magnetic force!!!"
Big Mom looks at Kid with disbelief.
Big Mom: "Are you still standing...!!?
Kid!!!"
Big Mom approaches Kid very angry. Kid has created something massive with metal objects he collects.
Big Mom: "So you want my head that much..."
Kid: "...!!
Hahaha... I already feel like we're doing this for a different purpose...
Kaidou must be NEAR to be defeated already.
If you let a drop of water fall onto a rock everyday, it creates a hole in that rock.
Hah. Hah.
Zero damage? There's no way you take no damage from all this fighting!!
“Punk Corna Dio” (Big Magnetic Demon Bull - 磁気大魔牛 (パンク コルナ・ディオ))!!!"
Big Mom: "Gyaa~~~!!"
Kid's created a giant metal bull (bigger than Big Mom) that he rides. Then he crashes the bull into Big Mom. She falls to the ground as Law and Kid talk to her.
Kid: "Hey...!! Damn old hag...!!"
Law and Kid: "We won't let you go on the rooftop
even if we have to die!!!"
End of chapter.
