Bleach's final story arc, the Thousand-Year Blood War arc, mainly focuses on brand-new characters such as the Sternritter and King Yhwach, while also exploring new sides to familiar characters like Captain Byakuya Kuchiki and even Uryu Ishida, Ichigo's friendly rival. This story arc still has room to bring back some familiar faces, though, and some of them are more relevant than Bleach fans would have expected. Ganju and Kukaku Shiba are two prime examples.
Source:https://www.cbr.com/bleach-ganju-and-kukaku-shiba-and-ichigo/