Then comes the neutral blades, Yubashiri and Shusui. The writer calls them neutral because neither of them are designed to be evil or righteous. The Yubashiri is described as swift sword and is extremely light in weight. The Shusui is heavy and is durable, which the opposite of Yubashiri. We all know that the Yubashiri didn’t survive pre-time skip, so its hard to say that Zoro had mastery over this particular blade.
Zoro has, however, completely mastered Shusui and the key to it is its weight.
During the timeskip, it has become Zoro’s go to sword and was used in most of his techniques. Zoro has turned Shusui’s heaviness into an advantage. Moreover, it is used to increase his cutting powers.