Beneath: The Inverted Church

From publisher blurb:

A serialized, mature tabletop campaign with 35+ maps for low to mid level characters. BENEATH can be played with almost any existing RPG system.

Beneath ancient ruins lies the UnDungeon, a "paradise" of unspeakable horrors. The Inverted Cupid, a demon of great power, is luring the local townspeople of CragLeee into the UnDungeon to create a master race of “…one race, one sex, one tongue". Only a band of brave adventurers can stop it. Follow Hannah, a fighter and resident of CragLee, as she guides you deeper into the UnDungeon to find her lost brother. Treasure can be found if you are willing to seduce your way through mirrorDoors or witness the atrocities inside The Invert.