Systematic Soul Sorting by Clinton Campbell

Elliot Archer struggles to deal with the aftermath of his best friend's death, and when he's at his lowest point he makes a difficult decision with irreversible consequences. Instead of nothingness, or perhaps the endless dark, Elliot opens his eyes to find a mysterious Grey Room slowly filling with people, and they all have weapons.

A dungeon filled with monstrous beings, murderous teammates, and a strange system reminiscent of an RPG, Elliot must find a way to rise to the occasion, or else he'll fall, again.