Full summary, thanks to redon from Arlong Park Forums.
Chapter 1,033: “Shimotsuki Kouzaburou”.
In the cover, Tashigi and Smoker are playing with some penguins in a frozen island. Tashigi is the villain who surrenders with a white flag (she wears a shark hat), the penguins are the heroes who defeat Tashigi (one of them is on top of Tashigi with a cardboard sword). Smoker is sitting in the background doing nothing, while a penguin looks at him scared.
Chapter starts outside of Onigashima's castle, where Zoro and King continue fighting. Zoro complains to Enma about having gotten out of control without permission and then he manages to pull his Haki back (Zoro's arm returns to its normal size).
King takes this chance to jump at him but suddenly, he stops in front of Zoro doing nothing. Zoro is surprised but he stabs his “Sandai Kitetsu” in King's belly. However, the attack does nothing to King.
King: "You hit the “right spot”."
Suddenly, there's a huge explosion where they are.
Cut to the “Pleasure Hall” in the Leftbrain Tower of the Skull Dome. Queen was hit so hard by Sanji in chapter 1,031 that he went through multiple rooms. Now he just manages to walk back to Sanji.
Did you just talk on the phone with “Pirate Hunter”!?
That guy cannot win against King...!!"
Queen: "King is a survivor from the extinct “Lunaria race”!!
They are the monstrous race that can survive in any condition in nature.
That's why they were called “god” by people in ancient time!!"
Sanji: "How did that kind of race go extinct?"
Queen: "Go and ask the history yourself!!!"
As Queen says this, we see that he opens his mouth to shoot a laser beam at Sanji.
Back to outside of Onigashima's castle. Zoro coated himself with Color of Arms Haki just on time, or else he would already be dead. King is in front of him, he's uninjured despite just blowing up himself.
Zoro attacks King again.
Zoro: "Ittoryu “Iai” (One Sword Style “Sword Draw”).
“Shi Shishi Sonson” (Song of the Death Lion Song)!!!"
Zoro attacks King point-blank again, but does nothing to him. King, without moving from the ground, transforms into a Pteranodon form and grabs the crest of his head again to attack Zoro point-blank with “Tempura Udon”.
Zoro draws his swords to counter King's attack, but Enma loses control and starts absorbing Zoro's Haki again.
Zoro: "Wait a minute!! Enma!!
Just in a moment like this!!!"
King: "“Tempura Udon” (Proud Imperial Marten)!!!"
Zoro cannot dodge it and he's partly hit by King's attack. The attack destroys part of Onigashima Island. Due to the attack, Zoro dropps his 3 swords.
King: "Ohh, a swordman dragged down by his own sword!!"
This is the first time I've seen something like that!!"
Zoro jumps down to the void to grab one of his swords.
Zoro: "“Sandai Kitetsu”!!"
While he's in the air, Zoro remembers the conversation he had with Hitetsu about that sword.
Hitetsu: "You already wield “Sandai Kitetsu”.
That is one of mine."
Zoro: "What, really!?"
Zoro also remembers how he got the sword in Loguetown.
Zoro: "This sword is bewitched."
Ippon Matsu: "Are you a fool? I can't sell you that sword!!
If you died, it'd be like I killed you myself!!"
Zoro: "I'll take it."
King flies up to Zoro and kicks him with a flaming attack that smashes Zoro. He was hit badly but Zoro gets up to grab another of his swords.
Zoro now remembers the moment when he got Kuina's sword.
Zoro: "Sensei!! May I have her sword!!?"
Koushiro: "... I suppose so..."
Zoro: "I'll have to keep the promise for both of us!!!
I'm going to become such a great master swordsman,
that my name will be known even in heaven!!!"
Zoro then remembers the other part of his conversation with Hitetsu.
Hitetsu: "You see, that white blade, “Wadou Ichimonji”, and “Enma”
... were both crafted by the same man!!
The blacksmith “Shimotsuki Kouzaburou”!!"
Zoro then connects the information about the origin of his swords.
Zoro: "That time I couldn't think about it because it was all too rushed...
But how come “Wanokuni” swords
ended up in the “East Blue”?"
King is in the air and attacks Zoro with a new technique called “Barizou Don” (Imperial Twin Blades - 刃裏双皇) with which he launches a burst of shock waves by flapping his wings. Zoro blocks the attacks, then he recovers “Enma”. But “Enma” starts sucking his Haki again.
King comes to where Zoro is and hits him with one of his wing. Zoro blocks the attack but the ground breaks and Zoro falls into an area inside the castle. As he falls, Zoro remembers a conversation he had with Momonosuke.
Momonosuke: "Zorojuurou, I was told not to say “sunacchi”."
Zoro: "It's just something the old guy in my village told me. I've never said it myself before."
Zoro remembers that he never knew the name of that old man who was always on the coast. On the day of his death, Zoro found out that the old man was Kuina's grandfather (we see a picture of Kuina with his father crying for her grandfather). Zoro remembers his conversation with Hitetsu again.
Hitetsu: "The blacksmith “Shimotsuki Kouzaburou”!!.
He broke the laws and left this land over 50 years ago."
Flashback starts, it takes place 13 years ago in Shimotsuki Village (East Blue). After losing again to Kuina, Zoro goes to the coast to continue training. There is the old man Zoro remembered (Shimotsuki Kouzaburou) and he teachs Zoro the word “sunacchi” (the old man says it in katakana (スナッチ) instead of in hiragana (すなっち) like Momonosuke).
Zoro asks the old man if he was once a samurai, since everyone in the dojo say it. Kouzaburou tells him not to say anything about it, or else the Marines will come for him. He then tells Zoro to turn around and leave. Zoro sticks out his tongue at the old man and leaves to continue his training.
Kouzaburou observes Zoro as he trains.
Kouzaburou: "Are you bored at the dojo?"
Zoro: "I lost again to Kuina!!
So I must keep training!!"
Kouzaburou gives Zoro two practise swords, Zoro is shocked and tells him that he has no money to pay for them. Kouzaburou tells him that it doesn't matter.
Kouzaburou: "These swords are the only thing I can make now...
Use them to practise.
Swords are “tools for taking lifes”!! Created to kill people!!
Blacksmiths design swords to take as many lives as possible!!"
Kouzaburou: "Each sword has its own personality
that the swordsman must learn in order to overcome it!!
A dangerous sword is a “cursed sword”!?
Foolishness!! “Cursed swords” are just “famed swords” that are feared by the weak!!
That's why they call them “cursed”!!
The sword is scary simply because it's performing its “duty” for it was made for!!
That sword I created when I was young, was the “masterpiece of my life”...
It was a sword that was so serious about doing its “duty”!!
I gave that “famed sword” the name of the King of Underworld!!!"
Back to the present. Zoro is lying on the ground with a surprised face, he finally understands everything.
The King of Underworld...
The name of the village is “Shimotsuki”.
So it wasn't a coincidence...?"
Zoro remembers how the children of Shimotsuki Village said that the village was created by pirates a long time ago (according to their grandparents). Then he remembers Hitetsu's words again.
Zoro: "So that old man who was a Wanokuni samurai...!!
He was the blacksmith “Shimotsuki Kouzaburou”!!?"
Zoro remembers other words from Kouzaburou.
Kouzaburou: "Famed swords are always watching human.
And will choose a swordman that they see fit...!!"
Zoro also remembers another Ippon Matsu's words in Loguetown.
Ippon Matsu: "A sword chooses its wielder."
Zoro looks at Enma, who is pinned to the ground. Despite not being in his hand, the sword is still active (it expels smoke) and Zoro's arm is still affected by Haki's absorption from Enma.
Zoro: "So it has finally come, the sword that has chosen me.
And is testing me...!!!"
Zoro grabs Enma, his arm returns to normal size. King is in front of him.
Zoro: "It's true... that a sword does not have any ill will by nature.
That means it's my power that is still not enough!!
Maybe Oden could fight with ease,
even with this much Haki was beking drained out of him...!? "
Is that right, Enma?"
Some Beast Pirates' subordinates approach the area to help King. Some of them believe that if they defeat Zoro, they will get a promotion. Zoro keeps thinking.
Zoro: "What should I do to stabilize my Haki...!?
If I allow this much Haki to be unleashed, it can end up taking my life."
Suddenly, Beast Pirates' subordinates start foaming from their mouths and fall down.
This is good the way it is!!"
Zoro stands before King. His 3 swords are covered with black lighting and smoke.
King: "I see...
So do you intend to become a “king”?"
Then, Zoro remembers the words Luffy said to him when Zoro agreed to join Luffy's crew.
Luffy: "The world's greatest swordsman, that's great!!
And it's fitting since your new boss is going to be the King of the Pirates!
Anything else would make me look bad!!!"
Zoro answers King with a smile on his mouth and a challenging gaze.
Zoro: "Yeah... I have a promise I made with my captain.
And my best friend!!!"