is bleach episode 306 filler?

Ichigo is surprised to see his inner Hollow, as he believed he destroyed him during their last encounter. The Hollow reminds him of his warning to him: to stay alive until the Hollow returned if he wishes to truly control his Hollow powers.

Ichigo asks the Hollow about his appearance with the horned mask, but it is Tensa Zangetsu who replies that this was Ichigo's appearance while he defeated Ulquiorra Cifer. Tensa Zangetsu adds that this was the form Ichigo feared would eventually crush his own soul, which in turn made it impossible for him to Hollowify properly.

Ichigo asks if he is meant to fight the Hollow again, but the two reply that instead he would have to face both of them as one.