Closed-Door Cultivation

"Why?"

Faced with Cang Nan's proposal, Aizen cast aside the so-called teacher-student relationship and asked directly.

"No particular reason. Throughout Soul Society's long history, the Soul Reapers' gaze had always been fixed on the World of the Living, yet they had never been able to see through the mist-like Negacion surrounding Hueco Mundo."

Cang Nan tilted his head to glance at Aizen and said meaningfully, "But this boundless desert is not entirely desolate. Hollows may be malevolent spirits born from transformation, but they are not utterly beyond saving—they still have room to evolve, to advance from Hollows to something nearly human..."

"What? If Hollows turn into humans, shouldn't that be..."