Holy shit that actually would make an awesome book plot. Like maybe some poor footsoldier gets killed in action and gets a humble funeral with only the basic necesseties to bury a body. He doesn’t even get a fancy tombstone with RIP or anything. Then suddenly his spirit gets thrust into some ugly, putrid, upside-down afterlife with ghouls and monsters shooting at each other. He just barely ducks down to avoid a ectoplasmic bullet and all of a sudden there’s this zombie dude with half his face rotted off yelling at him to ‘get up and fight you dumb kid!’
The zombie dude is actually an old war vet from WWII and he’s been part of the skeleton war for longer than he can remember. The skeleton war is actually just a bunch of dead guys spending their afterlife fighting supernatural horrors and keeping them from entering the world of the living. It’s a thankless task and sometimes they let a few ghouls slip past them on Halloween, but it’s war. War is always a thankless task no matter if you’re dead or alive.