"Hollows are the souls of humans that have not found the piece of Soul Society and so evolve into monters that prey upon the souls of humans. The hollow hole is where I, in my previous form was bound by and spirit chain which tore this hole in me, rendering me hollow and a monster. I however have gone thrugh many transformations since my hollowfication. Ascending to become a Menos Grande, a Vasto Lorde class, the strongest of the menos. Lord Aizen gave me even more power and a purpose when he turned me into this." He gestures lazily to himself. "I was made an Arrancar, a hollow with the powers of a soul reaper yet now I transend both. Lord Aizen even saw fit to make me Espada number 4." He pulls his white cloak back to reveal the number 4 tattooed onto his upper left chest. "To be hollow is to be forsaken from paradise and for theat we despise Soul Reapers."