According to the search results, the Zero Squad is a group of powerful Soul Reapers who serve as the last line of defense for the Soul Society and the entire Bleach universe. They were introduced in the manga as a big deal, with Shunsui claiming that the five had enough military power to outclass everyone in the Gotei 13 combined. However, they were defeated quickly and without any significant victories when Yhwach and his Schutzstaffel invaded the Soul King Palace. Nimaiya was killed instantly by Lillie Barros "The X-Axis," and Hyosube fared no better against Yhwach. While Hyosube was able to hold his own against Yhwach, the other members of the Zero Squad were defeated and killed. However, the light novel Can’t Fear Your Own World, which is considered Canon by Kubo, revealed that Hyōsube later revived the Royal Guard. Each member is fused with their palace, and as long as the palaces exist, they can be revived. It is unclear whether they are still serving or not.