Shusui

Shusui was the legendary sword that was used by to defeat a dragon centuries ago. Although the sword was later stolen by, a former Shichibukai who was known as a grave robber, returned Shusui to Ryuma's grave in Wano Country during their battle against the former Yonko,. However, during the course of the Wano Civil War, Ryuma's grave was disrupted and the sword was misplaced and thought to have been lost forever. During his expeditions across the New World, Almasy D. Laszlo uncovered the sword, and supposedly fled from Wano. Since then, he has been the sole user of the Black blade.