Known as Dancing Blade, this move involves a sequence of sword attacks performed by Marth. A maximum of four attacks can be chained together with the move, with different directions allowing different attacks for all attacks except the first. This makes the move very versatile and somewhat unpredictable if used correctly. However, connecting the hits often requires good memorization of the timing windows.
The first hit of the move has pseudo-jump properties and even with subsequent uses will lower Marth's falling speed in the air, which is useful for recovery, as it gives a bit more horizontal distance. In addition, the third parts are particularly useful due to being able to KO and tech-chase. Overall, how good the move is may depend on the player's opinion - it has many uses, but isn't too easy to utilize, plus isn't used too often as Marth often has superior options.