Book of the Dead is a Manwha that takes place entirely in the afterlife/purgatory, compromised entirely of young souls which killed themselves

This Manwha has a whole lot of Gore, Psychologically focused themes and surpassing trauma

The original Korean sources were NSFW with nudity but it has been cropped for the English translation

I had been searching for a long time for a Manwha like this, and when I originally found it, it only had 6 chapters so I felt like I had **won the lottery

if the gore and traumatic aspects are not a trigger for you, I suggest you check out the first four chapters