'Gabriel/Gabrielle (aka "Gabe") is an Angel and is therefore physically genderless. He/She has no free will and there is an unknown force that drives him/her to do good and protect the innocent; Gabe assumes this force is divine. Gabe hates not having any free will, so he/she tries to get rid of this instinct by drinking, smoking, and gambling. He/She collects various religious artifacts and believes in all religions at the same time.'
(As according to the official site.)
Further detail[]
Gabe has been shown to be on relatively friendly terms with The Grim Brothers, playing poker with them on occasions and The Bloodcarver, who confessed to him/her his worries for the future.