If souls enter devolution by losing their humanity and humanoid form, what forms are typically taken once within the averno? Western and Eastern religious paintings always depict beings in hell in the human form...
Nothing can completely describe the horrors of the Averno, because astral entities take on a multitude of forms. Artists have merely approximated, so that anyone with an awakened consciousness would recognize such terrors, a dread reminder to never stop working on themselves.
Hieronymus Bosch provided some weird and disturbing depictions, which are also very accurate.