The Dread Below is a Forge 1.21.1 horror mod built around paranoia, darkness, and cursed survival.
It adds haunted blocks like Bloodstone and Screaming Wood, cursed relics like the Cursed Heart, Dread Knife, and Watching Eye, plus an ambient horror system that stalks players underground and at night. Expect sudden darkness, nausea, heartbeat sounds, warden-like audio scares, sculk soul particles, action-bar whispers, and cursed effects when using or carrying the relics.