Odc. 309: Ichigo uwalnia Final Getsuga Tenshou, by uwięzić Aizena z pomocą Urahary.

309

Ichigo wounds Aizen, forcing the Hougyoku yet another transformation upon Aizen, who becomes a hollow-like creature. Although Aizen renders Ichigo's left arm useless, Ichigo then unleashes the Final Getsuga Tenshou. Through a flashback, it is revealed that while in his inner world, Ichigo could not defeat Tensa Zangetsu until he allowed to be pierced by Tensa Zangetsu, thereby accepting the blade and the consequences of the technique. Unleashing this attack allows Ichigo to actually become the attack itself, which would strip him of his Soul Reaper powers. He unleashes a torrent of darkness that enshrouds the land and overwhelms Aizen. However, Aizen prepares to finish off a weakened Ichigo thanks to the Hougyoku, only to be stopped by Urahara, who steps onto the scene. Urahara planted another kidou inside of the kidou he shot just before Aizen transformed the first time as a sealing process. Now that his power has been weakened by Ichigo, the seal has begun to work and the Hougyoku no longer sees him as its master, resulting in him being sealed. (Source: Wikipedia) Arrancar: Downfall arc: (38/39)