Bleach Episode 166: Desperate Effort VS Desperate Effort! The Hollowized Ichigo
Episode 166 of 366 of Bleach, aired April 9, 2008, 24 minutes. Available with English subtitles and dub where released.
Episode summary
Ichigo pulls out his Hollow mask and Grimmjow releases his sword, Pantera. With both in their most powerful forms, the battle begins in earnest again. The fight is intense with both sides exchanging strong blows. As Ichigo's mask breaks apart bit by bit, Nel urges a frightened Orihime to cheer for Ichigo since he is doing it for her.