Arc 35The Hollowfication Experiment
Allen joined Aizen’s campaign against Soul Society, helped defeat its leaders, and then pursued his own plan to create and absorb a Hollow counterpart using the Hogyoku. After surviving Hollowfication, he returned to Las Noches and began guiding the Espada toward deeper transformations.
- Sakura revealed herself as a Quincy and fought Byakuya, while Allen took Rukia to Soul Society under the Central 46 execution order.
- Allen killed the Central 46 and joined Aizen’s operation, then tested Ichigo and fought Kenpachi before battling Unohana at the Chambers.
- Aizen revealed his betrayal and took the Hogyoku from Rukia, while Allen fought Ichigo and the captains and killed Yamamoto before escaping with Aizen.
- Allen hunted Hollows in Hueco Mundo to create his own Hogyoku, then confronted the Arrancar in Karakura Town and explained his plan to Ichigo.
- Allen separated Ichigo from White Ichigo and used the Hogyoku to begin his own Hollowfication, while Sakura, Artoria, and Vilnalasath restrained his rampaging body.
- Allen defeated and absorbed his Hollow counterpart, but learned that repeated use of Death’s Bankai was eroding his soul, after returning to normal, he warned Ichigo and his friends about Aizen’s interest in Orihime.
- Allen returned to Las Noches with Ulquiorra and Nnoitra, gave Aizen his Hogyoku, and revealed their advanced Resurrección forms.
- Allen began guiding Grimmjow through a deeper transformation, urging him to focus his mind as the Hogyoku’s power drove him through a painful change.