Denizens of the kingdom below the river: the shade and the ghul
Hell overflows. No wonder its denizens all try to flee.
Shade
HD 1 (though the shades of great heroes are far more weighty)
AC as unarmored
Damage 1d6, ignoring physical armor
Mind fleeting, cloudy
Voice gone: silent unless substantiated by blood, either red or black
Runs as fast as a human can, just without regard for gravity or physical barriers
Incorporeal and unharmed by unblessed weapons.
Becomes invisible at will.
Cannot cross running water, nor objects painted to resemble running water.
The first time someone beholds a shade, they must roll breath or age 2d10 years and flee, their mortality affirmed.
Incorporeal spirit of the dead, appearing as a faceless breath of mist. Mindless and placid, mostly, when encountered either in the underworld or on their way there. But sometimes a shade is purposefully prevented from reaching hell, gets lost on the way there, or isn't properly buried and becomes unable to pay the doorkeeper's toll. This liminality is torturous—no wonder they lash out.
If reduced to zero hit points, a shade is temporarily banished, but returns within a day. A shade haunting the earth can only be given death by solving the problem of its displacement (e.g., a lost shade must be guided to the underworld, while a shade whose corpse remains unburied must be present for its proper burial rites).
Appears alone (5-in-6), or otherwise in a throng of 1d100 at the site of a horrendous slaughter.
Ghul
HD 2
Damage 1d6
Mind panicked and starving, but newly-empowered with man's cunning
Voice slurred: slowly remembering how to operate its own body
Climbs sheer surfaces as fast as a human can run
A living person touched by a ghul must roll breath or be paralyzed with impending mortality for a combat round. Alternatively, they can choose to push past this paralyzation and act normally. If acting normally, reduce maximum HP by 1 until at least a day is spent in sunlight, amongst cheerful company, and in a safe and comfortable place. Maximum HP reduction is cumulative, but recovery time is not.
Spirit of the dead that has consumed the black blood of the underworld and taken physical form. An overpowering fear of death often comes alongside it. Losing everything is all the more terrifying when it’s been experienced once. Once no more black remains, they must seek the red.
There is a period of pacified contentment in the wake of experiencing human pleasures like sex or food that can be exploited by a cunning magician.
Appear in packs of 3d10. A pack on the verge of starvation will turn on itself.