Beat the Invisible Enemy!

Rukia and Chad battle the Hollow Shrieker which has haunted the "Cursed Cockatiel." They fight even though Rukia's powers still have not completely returned, and Chad is unable to see Hollows. But this Shrieker has beaten many Soul Reapers and committed countless sins. Meanwhile, Ichigo is taking Natsuki home after she collapses from the shock of seeing the tragic memories of a boy spirit inside the parakeet. And he has no idea of the danger that Rukia and Chad are in.Source: crunchyroll