Enma is a katana with a trefoil-shaped tsuba.[1] Its hamon has a flame-like pattern.
Abilities
Being of the O Wazamono grade, Enma is among the finest blades in the world, shown by how Kozuki Hiyori considers it good enough to be a worthy replacement for Shusui. Indeed, in the hands of Oden, Enma became the only weapon known to have ever harmed the nigh-invulnerable Kaido, a Yonko, giving him his only scar.[3] True to Hiyori's words, Enma demonstrated power and sharpness far surpassing Shusui, as when Zoro tried to cut a tree he ended up cutting a whole cliff off. Tenguyama Hitetsu described its power as being able to cut through Hell itself. Hitetsu also states that if Zoro manages to turn Enma into a black blade, it may increase its rank to one of the 12 Saijo O Wazamono.[2]
The sword forces its user to release excessive amounts of Ryuo (Busoshoku Haki) causing unnecessarily large strikes. The amount of Ryuo released will cause an ordinary swordsman to collapse immediately.
The sword originally belonged to Kozuki Oden, who later used it to wound one of the Yonko, Kaido, giving him his only scar. After his death, it was passed onto his daughter, Kozuki Hiyori.[3]
Wano Country Arc
After Hiyori begged Zoro to leave his stolen Shusui in its rightful place on Wano, she offered Enma as a replacement.[3] Zoro agreed to Hiyori's proposal of leaving Shusui for Enma.
Trivia
Enma is the king of hell (jigoku) in Japanese-Buddhist myth, the foremost judge of the newly dead. He sentences the souls of man to punishment for their earthly sins within eight hells, until he deems them ready to move on to their next location (such as return to the cycle of reincarnation). Enma is the Japanese version of Yama, the king of hell found in sects of Buddhism across East Asia; he mostly derives from the Chinese-Buddhist Yanluo, who in turn is based on the Hindu (Vedic) god of death, also called Yama.
In Chapter 920 and Episode 893 a flashback of Oden is seen wielding a sword with a different tsuba. Whether this is a mistake or another sword is unknown.
On the cover of Chapter 937, Roronoa Zoro was seen reading a map featuring a sword and the word "Enma".
Enma is also the name of the shrine in the forest where Hiyori and Zoro end up in Chapter 950.