The Bleach: Thousand-Year Blood War season 2 finale put Squad 0, the strongest Soul Reapers in all of Soul Society, in the spotlight, and here’s a breakdown of all of their powers. Also known as the Royal Guard, Squad 0 consists of the five Soul Reapers tasked with guarding the Soul King. The members of Squad 0 were chosen for creating something fundamental to Soul Society. They’re also the most powerful Soul Reapers in the setting, their combined power surpassing the entirety of the Thirteen Court Guards; the anime further reinforced that by revealing that the members of Squad 0 have to place a seal on their powers because fighting at full strength would destroy the three realms of Bleach’s universe.
https://screenrant.com/bleach-thousand-year-blood-war-squad-zero-powers-explained/