For the majority of the series, Bleach centered around the conflict between the Soul Reapers and Hollows, but the Thousand-Year Blood War arc dealt with the war between the Soul Reapers and Quincy. The Sternritter are the strongest members of Yhwach's Quincy army, and they decimated Soul Society during their invasions. Every Sternritter is incredibly strong, but some are far more dangerous than others.
Source：https://www.cbr.com/dangerous-bleach-sternritter-tybw/
