Mugetsu

Mugetsu is 's Final Smash in Super Smash Flash 2.

Overview
When performed,Ichigo enters Getsuga and generates a blade of deep black Reiatsu in his hand, then swings it creating dark veils of Reiatsu on the ground that travels forward as it damages opponents.

Origin
Mugetsu, aka the Saigo no Getsuga Tenshō, is Ichigo's strongest Getsuga Tenshō. By using this technique, Ichigo becomes the Getsuga itself. It is referred to as the “Final” Getsuga Tenshō because if Ichigo uses it, he loses all of his Shinigami powers. Because of this, Ichigo was only able to use it once, which he did against Sōsuke Aizen in episode 309 of the anime Bleach.

Trivia

 * Prior to Beta 1.2, Ichigo's Final Smash was instead a Transformation Final Smash called Bankai Ichigo. It was changed to Mugetsu possibly due to its immense power and outdated sprites.