Sojiro Kusaka

Sōjirō Kusaka (草冠 宗次郎, Kusaka Sōjirō) is a rogue Shinigami and a childhood rival of Tōshirō Hitsugaya until his alleged death at the hands of the Central 46 for sharing the same Zanpakutō, Hyōrinmaru, as the latter. He would survive in Hueco Mundo with the power of the Ōin and plot his revenge against Soul Society by stealing the artifact and unleash its power with Hitsugaya's cooperation.