Hollows in Bleach are born from lingering souls consumed ... They were later turned back to normal by Kisuke Urahara but acquired Hollow masks and powers. Shinji Hirako is the leader of these.

In Bleach TYBW, he showed that ... The Vizards unleash their Hollow powers by wearing a Hollow mask, much like Ichigo Kurosaki used to do. Unlike the protagonist’s early unstable transformation ...