This is Episode 20 of Season 13, which is a filler arc known as the Zanpakutō Unknown Tales arc. Characters Involved: Muramasa: The main antagonist of the arc.
The episode begins with Uryū, Chad, and Orihime meeting Muramasa, who has entered the World of the Living to further his plans. Bleach (Dub) Episode 249
Providing the primary defense against the threat in the human world. Senbonzakura: A key physical manifestation of a Zanpakutō. This is Episode 20 of Season 13, which
For fans following the series' production history, this arc was a major deviation from the manga's Arrancar storyline, designed to allow the manga more time to progress. Bleach 249 - BLEACH (Season 13, Episode 20) - Apple TV and Orihime meeting Muramasa