This is how Black Blades are formed
I was wondering why Saint Ethanbaron V. Nusjuro didn’t have a black blade. This led me to a theory: maybe you need to defeat Death itself to turn your blade forever black.
Zoro saw the Grim Reaper in Wano, it was his chance, but Zoro was weak at that moment and could not even move. In the anime, we saw Death deal its hand and break the rock underneath Zoro, causing him to fall from Onigashima. The only reason Zoro survived is because Franky caught him.
What if, next time Zoro sees Death, he is actually able to move and fight it, defeating it and turning his blade permanently black—a sign of a swordsman who can defeat even Death itself?
Saint Ethanbaron V. Nusjuro not having a black blade is even more impressive. No one has ever been able to push him to that point. He never had to face Death.
