Rasetsusen

Rasetsusen (螺刹旋) is the technique Zero and Layer obtain after defeating Dark Mantis in Mega Man X8. Zero performs an airborne dark-element spinning slash attack that can be directioned downward and diagonally down. If no button is pressed, the user will stay in the air for a short period before moving down. 

Glitch
If the player press the down button while holding the up button, the user will move straight up instead of going down, making it possible to reach high areas and even go out of the stage's limits. The glitch can be used with any weapon and Senpūkyaku, and can also move diagonally up. 

Trivia

 * Unlike Shadow Runner and Black Arrow, Rasetsusen does not have any shadowy/darkness visuals like the others do.
 * If both the up and down button are held whilst performing Rasetsusen, the player will move vertically until the attack is manually stopped.