Heaven EditNot much is known about Heaven, as it was not shown much in the manga, except that Archangel Raphael oversees it, and also where God and angels reside in.
This is where spirits enter to overcome numberous of trials and tribulations to gain two types of body: human or azrael.
Where most of the manhwa's story takes places in and also where demons, witches and devils reside in. To guard the "Master of Archdevils", Archdevil Mastema placed multiple gateways between each floor of Hell to prevent beings, especially Angels, from traversing the floors of Hell easily and reaching the "Master". It is also known that Archangel Michael presides of this section of the Underworld.