Bleach: The Two Gods of One Family Novel

The protagonist travels through Soul Society only to discover they have a brother, Aizen Sōsuke, who is determined to surpass them. Facing the strongest Shinigami Yamamoto and the sleeping Yhwach, the protagonist feels immense pressure. However, their power lies in their Zanpakutō, Reiatsu, and combat abilities—Zanjutsu, Hakuda, Hohō, and Kidō—which all train independently and compete fiercely with each other. Their Zanpakutō is extremely intelligent and has mastered Bankai on its own. Reiatsu refuses to fall behind and has broken the limits of Shinigami strength. Kidō is highly motivated and has created its own forbidden spell. As a result, even Aizen acknowledges there is no rival before his brother. Yamamoto recognizes the protagonist as the strongest Shinigami, while Unohana finds them pleasing. Ichibē believes that before this person, rules themselves cease to exist.