Hollow Kezo Is the inner hollow within Kezo Zakara he is a powerfull dark entity that was born when Kezo was hollowfied yet it is unknown when or how it happened, Hollow Kezo apears to be created mostly by the inner darkness within Kezos soul and seeing he is very powerfull it could mean that Kezo has alot of darkness within hes soul and even after controlling the hollow mask Hollow Kezo is still within the body and soul of Kezo waiting for the right moment to take control.