Arc 11The False Death and New Alliances
Yan Si prepared Soul Society for Aizen and the Wandenreich, then staged his death after fighting alongside Unohana and Zaraki in Muken. Living as a human with Yoruichi, he continued to work with Aizen and investigate the Quincy threat as Masaki Kurosaki and Isshin became involved in the coming conflict.
- Urahara Kisuke fled Kaname Tōsen in Las Noches, while Aizen revealed to Yan Si his plans to evolve through the Hogyoku and eventually attack Soul Society.
- Yan Si and Urahara rescued Kuroyashiki from Starrk, then Yan Si warned Soul Society’s leaders about Hueco Mundo’s growing strength and helped them prepare for Aizen and the Wandenreich.
- Yan Si pursued plans to strengthen the Shinigami, helped Tōshirō Hitsugaya graduate and awaken Daiguren Hyōrinmaru, and learned the Shiba family’s Humanization Technique.
- Yan Si gave Soul Jades to Byakuya and Mayuri, asked Urahara to make him a human body, and promised Yoruichi that he would leave Soul Society with her.
- In Muken, Yan Si fought Unohana and Zaraki, helped them evolve with Soul Jades, and secured their promise to delay their duel until after the Wandenreich was defeated.
- Yan Si’s staged death prompted Gin to attack Zaraki and Yoruichi to challenge Unohana, while Chiziro Kenpachi and Amatsuyu Takuru revealed that the apparent corpse was a puppet.
- Yan Si met Aizen in his bookstore after leaving Soul Society, and the two later agreed to become Transcendents and coordinate an attack on Yhwach when he reclaimed his power.
- Gin gave Rangiku a Soul Jade, Urahara went to protect Masaki Kurosaki, and Yan Si gave Masaki a protective charm and a story about Husky Bach as she grew closer to Isshin and Ryūken.