In One Piece we've learned to rate swords by their quality as Meito graded swords. Mihawk and Whitebeard both had swords in the top Meito class, the best 10 swords in the world, and we knew this was because their swords were the strongest in the world.
So why is Zoro suddenly so much stronger with Enma? It's the same Meito grade as Shusui. It should be a sidegrade, or somewhat close in power, and not this overwhelming upgrade like it's being presented. I no longer understand what the different sword grades mean anymore.
Can someone explain why two swords of the same meito class could be so different in power? Is the meito class a flawed indicator of strength, and it was just coincidence that WB and Mihawk both have swords in the top 10 Meito class?
Enma and Shusui are both O Wazamono or Great grade swords. Enma has shown to be far stronger than shusui. As stated on the wiki page, Enma is the only weapon in the series the directly effects the user Haki on its on accord, which means that Enma is the only weapon so far with a unique ability. Shusui is already a "Black Blade" and we've seen that in the hands of Zoro that it can further be blackened with Haki/Busoshoku Haki. My guess and this is my theory, before becoming a permanent black blade, Shusui aas one of the Ryo Wazamono or Skilled grade swords. The lastest chapter gave us new information. When Enma is turned into a permanent "Black Blade", it will rise in rank to Saijo O Wazamono or Supreme grade sowrds. Even though there the same class, Enma has yet to become a "Black Blade" when Shusui already is, and I highly doubt we've seen Enma used on a mastered level yet so im sure even greater feats than last chapter are waiting. Besides Zoro's feats from last chapter are greater than anything he's done up til now in the enitre series in my opinion and that was just an accident with just one sword. Im sure Enma will become Zoro's favorite sword once he's mastered it and he will have a Saijo O Wazamono or Supreme grade sword to battle Mihawk with.(Cman12 (talk) 05:49, September 18, 2019 (UTC))