One Piece'sZoro is a member of the Straw Hat Pirates and an incredibly powerful combatant who wields three swords in combat. Ever since a very young age, he trained at a dojo in Shimotsuki village where he learned the way of the sword under Koushiro, the dojo master. By the time his training ended in the village, Zoro has mastered the Three Sword Style and acquired Wado Ichimonji, a powerful O Wazamono grade sword, from Koushiro. With the Wado Ichimonji, he aimed to fulfill the promise of a lifetime to Kuina and become the greatest swordsman.
Zoro has become extremely skilled and advanced his skills enough to the point where he's even earned the praise of someone like Dracule Mihawk, the World's Strongest Swordsman. Over the course of the two-year timeskip, he has only gone from strength to strength and acquired even greater skills, boosted further by his ability to use Haki. While all that certainly makes Zoro a phenomenal swordsman already, it wasn't until the Wano Country arc of One Piece that he ended up taking the biggest step towards his dream of becoming the greatest swordsman in the world, and all that came through a newly acquired sword that once belonged the legendary Kozuki Oden – Enma.
What Is The Sword Enma?
Crafted by none other than the legendary swordsmith Shimotsuki Kozaburou, Enma is one of the 21 O Wazamono grade swords to exist in the world of One Piece. Kozaburou forged his sword when in Wano and to the day of his death, he remembered this blade as his greatest creation. According to Kozaburou, Enma is a sword whose disposition is deadly serious. Just holding this majestic blade in one's hand sent shivers down the spine, which just goes to show how powerful this sword truly was.
Being the greatest creation of Kozaburou, Enma ended up becoming a blade with tremendous power and earned the reputation to be able to cut down to the bottom of hell, another indication of its ferocious powers. Kozaburou named this sword Enma since it holds the power of the King of the Underworld. Only the truly powerful can conquer this sword as it is extremely difficult to master.
Enma is a special sword and, unlike any other blade seen in the series, drains the Haki from the body of the user. For any average Samurai, holding Enma just for a few minutes would spell death. However, for skilled users, Enma is a weapon that can only add to their power when tamed.
That said, taming this sword is easier said than done. For Zoro, taming Enma took quite a lot of time, and even after his days of training before the Fire Festival and the Raid of Onigashima, he couldn't get a perfect grasp over its abilities. After finally allowing Enma to absorb as much Haki as possible, Zoro was finally able to take the next big step as a swordsman and defeat even someone as strong as King the Wildfire of the Beasts Pirates, a man worth 1,390,000,000 berries.
The Users of Enma
While Enma is currently being wielded by Roronoa Zoro, he wasn't the first user of this powerful blade. For years, this blade was in the usage by the strongest Samurai of Wano Country, Kozuki Oden. It is believed that Oden wielded both Enma and Ame no Habakiri from a very young age – a feat that is certainly not easy to pull off and only goes to show how monstrous a samurai he was even as a mere child. Over the years, Oden grew tremendously powerful with this blade in his possession. Clashing blades with the likes of Whitebeard and tussling for supremacy against Roger, Oden only grew stronger with time. By the time he returned to Wano, he had become several times more powerful than he was when he left and his swordsmanship skills were also at their peak.
He eventually fought Kaido in combat and using the power of Enma, could scar him and nearly kill him. This is a massive feat that no other person in the One Piece world had pulled off at that point. After his unfortunate defeat to Kaido, Oden then passed Enma on to Hiyori, his daughter. 20 years later, Roronoa Zoro visited Wano Country with the Straw Hat Pirates and ended up trading Shusui for Oden's beloved blade, Enma.
Under Zoro, Enma was quite a beast to master and would suck more Haki from his body than needed. As such, it took him quite a lot of time to master it. Even when he fought Kaido on the rooftop, Enma hadn't been fully tamed. After receiving quite a hellish beating against King the Wildfire, Zoro finally understood how to handle the sword. By allowing it to suck Haki from his body unrestricted, he was able to master the sword for good. In doing so, Zoro also allowed the blade to bring out his Conqueror's Haki and use its advanced form. The only downside of having Enma was that Zoro couldn't fight for long using this sword as the amount of Haki that it drained from his body was simply too great.
As such, Zoro only lasted a few minutes in combat against King and would've died if he continued longer. Nonetheless, those few minutes at the peak of his power were more than enough for him to defeat King, all thanks to Enma. It goes without saying that Oden's beloved Enma is a majestic sword that not everyone can wield in combat, however, it makes the strong personalities, such as Zoro and Oden, even stronger. Although not a Saijo o Wazamono grade, Enma is truly a ferocious blade that has rightly earned the title of King of the Underworld. Thanks to it, Zoro has also gained the moniker of "King of Hell." In time, Enma will become a black blade, meaning it'll get even stronger and when that happens, it'll advance in grade as well, making it one of the Saijo O Wazamono grade swords of the One Piece world.