The heart of this episode is the clash between and his superior, Captain Byakuya Kuchiki . Driven by a lifelong vow to surpass the man who took Rukia away, Renji finally reveals the fruits of his training: his Bankai, Hihiō Zabimaru .
Despite Renji’s incredible willpower and new Bankai, Byakuya demonstrates the overwhelming difference in "class" between a Lieutenant and a high-level Captain, ultimately overwhelming Renji with his own Bankai, Senbonzakura Kageyoshi . Training and Treachery
In of the Soul Society: The Rescue arc , titled " Renji, Oath of the Soul! Death Match with Byakuya ," the tension reaches a breaking point as the looming execution of Rukia Kuchiki draws the series' key rivals into a final, bloody confrontation. The Ultimate Rivalry: Renji vs. Byakuya