As the mysteries of Bleach's "Thousand-Year Blood War" arc continue to unravel, the story grows more complicated. Fans are left with a lot of questions about Uryu Ishida's shocking decision to join the deadly Yhwach and become a Sternritter. Of Ichigo Kurosaki's many friends, Uryu is among the most powerful and the most intriguing. The series shows his tremendous growth in every arc, making him all the more likable. In terms of strength, Uryu is Ichigo's only friend who can regularly fight side-by-side with him.
Source：https://www.cbr.com/bleach-tybw-uryu-ishida-betrayal-explained/
