Unlike Sanji and Luffy, Zoro has not been taken to the limit after the timeskip but that’s all about to change since Wano arc could be where Zoro is taken over his limits.
BLACK BLADE THEORY
To start this off let’s talk about Dracule “Hawk-eyes” Mihawk who holds the title of the Greatest Swordsman in the World.
He’s respected by literally everyone from Yonkos like Shanks and Whitebeard to Admirals like Akainu even by the Warlords like Hancock and Doflamingo.
This is Mihawk’s main Sword is one of the twelve Saijo O Wazamono and a “Black Sword/Blade” (Kokutō). The only other Black Sword is Shusui which belonged to Ryuma and is now owned by Roronoa Zoro.
The Difference between Yoru and Shusui is that Yoru is a Supreme grade Sword and Shusui is a Great grade Sword but that’s not what makes these 2 special.
EVERY WEAPON CAN BE TURNED INTO A BLACK BLADE LIKE MINE• Mihawk stated that it can become the black blade like mine meaning that Yoru was once normal but he managed to turn it into a black blade.
Almost all top tier swordsmen are able to clad their swords with Haki and that becomes a Black Blade but it doesn’t last for a long time and it becomes a regular sword which allows that sword to be broken.
Mihawk and Ryuma were able to make that permanent.
How did Ryuma do it?
From Chapter 937 we discovered one thing:
Shusui is a BLACK BLADE. It became one after its many battles alongside Ryuma. Alright we also found out that Ryuma had a much more important role during his time.
Protector of Wano
There were so many pirates who wanted it all for themselves..! And so many nobles who wanted to bring this place under their control..!!Ryuma was the one who protected Wano from any outsiders meaning he had battles with Top Tier Pirates of his time and Marines and Government Agents and Higher ups who were sent by the nobles to obtain the treasure that lies within Wano.
He was constantly in Battles with powerful people and like he said it became permanent after all these battles.
This also means that Shusui is clad with Ryuma’s Haki meaning that it could be stronger or at the same level of Mihawk’s Yoru and making it stronger than Zoro’s Wado Ichimonji and Sandai Kitetsu.
How did Mihawk Obatin it?
Mihawk is the current Greatest Swordman and the only known person other than Ryuma to have the Black Blade.
This could be due to his multiple battles and rivalry with Shanks.
In the past, they sought out each other on many occasions to duel. Their battles were said to echo through the whole Grand Line.
However, Mihawk has given up on trying to fight Shanks after he lost an arm. That didn’t stop Mihawk from finding someone to replace Shanks to have a challenge with.
There are people who dreamed of dueling with Mihawk during the war: “Flower Sword” Vista said that he has always dreamt about having a duel with Mihawk as there were others.
There are also other Top Tier Swordsmen who want to take his title like Zoro. This could mean that Swordsmen like King could have challenged him to a duel?
So “Sword God” Ryuma the King managed to get the Black Blade through fighting off people who were trying to get into Wano.
Dracule “Hawk-eye” Mihawk managed to get the Black Blade through battles with Shanks and then dueling with Top Tier Swordmen and by beating anyone who dared to challenge him.
RORONOA ZORO – THE GREATEST CHALLANGE
So far Zoro has not been taken to his limit but Wano arc is not going to be built upto Zoro Vs King since he’s going to have multiple battles this arc:
If you count the Top Tier Swordsmen in Wano he could have several battles.
His lack of direction could lead him to find and face these people:
JACK “THE DROUGHT“
KING “THE WILDFIRE”
This is going to be one of the most epic battles in Wano next to Luffy Vs Kaido.
This will be at the end of the Arc or during the Fire Festival, possibly Zoro’s Final Duel in Wano. And could be the hardest where he could be taken to his limits.
“SHOGUN OF WANO” KUROZUMI ORCHI
Defeating Orochi could prove to Wano that Zoro deserves Shusui.
A spineless brat like you had no right to this sword! This is how the people of Wano feel about Zoro having Shusui.
And even if the Straw Hats win they won’t let Zoro get away with Shusui unless he proves that he deserves Shusui.
BLUE FLAMES THEORY
The blue flames of Ryuma could be due to Shusui and Zoro is able to activate this after the timeskip
Ok this was a comedic moment but when Zoro got fired up he had blue flames similar to Ryuma and he had an attack called Blue Dragon Seal where we see it again and we also see a dragon
Could be spirit inside Shusui and his mastery of Shusui could earn him Shusui.
ZORO VS OROCHI
Zoro vs Orochi is going to be the modern day Ryuma Vs Dragon.
This could mean the people of Wano could finally say that Zoro deserves to hold Shusui.
Wado Ichimonji and Sandai Kitetsu?
Mihawk and Ryuma both had battles with a lot of Top Tier people and Wano arc is perfect for Zoro to have multiple battles with a lot of Top Tier people and that could make both of them turn into a Black Blade.
Zoro defeating King and Orchi would get the attention of new and old opponents:
Shiryu of the Rain
Their battle would be built around Zoro mastering Observation Haki since Shiryu is now using Suke Suke no mi making him invisible and he’s already known as the Stealth Master.
They had a minor clash in Dressrosa and since he’s ordered to chase down the Straw Hats he could have interest in clashing with Zoro once again after hearing the news.
*Theory by King of beasts kaido