Bussengeist

A bussengeist is the ghostly remnant of a person who died in a great calamity that he or she helped bring about, through action or failure to act. It looks much as it did alive, though partly transparent. Witnessing endless misery wears on it, and its face grows sad and drawn, so these heralds of ruin usually seem much older than their age at death. They communicate through limited telepathy, but nearly always share only grim warnings of what is coming, never anything that might help prevent it.

A bussengeist never fights. Its fate is to watch, over and over, the kind of disaster that killed it. When it arrives at a scene of destruction, it radiates an aura of despair that affects only one side of a conflict, usually the side closer to good. Every creature within 120 feet suffers -4 on attack and damage rolls, saves, and proficiency checks, and the DM may penalize other rolls too. A successful save vs. spells avoids the effect.

Physical weapons cannot harm it, and turning undead does nothing, but some spells can drive it off or even end it. Dismissal, limited wish, holy word, or control undead cast by a priest or wizard forces it away, though it returns in 2-12 hours and is then immune to that same spell from the same caster. Forbiddance keeps it out of an area for the spell's duration. Only wish or dispel evil can destroy one.

Bussengeists wander alone, but unlike ordinary drifters they cannot choose their path. They are dragged from one tragedy to the next and made to watch destruction like the one that ended their lives. Generally only those who feel remorse become bussengeists. Consider a traitor who opened a city's gates to invaders and died in the fighting. Killed suddenly and without pity for those he harmed, he would not return; but if he saw death coming and had reason to regret his choice, he might well rise as a bussengeist, doomed to visit cities sacked by barbarians, castles overrun by monsters, and the like.

They travel in an insubstantial but visible form and begin radiating despair only once they reach their destination. After the disaster that drew them has happened, they feel the urge to move on and plod slowly toward the next one. They usually appear 1-6 days before the event, giving locals a warning, at least those wise enough to recognize the sorrowful specter for what it is.

As an unnatural being it has no place in the world's ecology, but history is another matter: many scholars point to great battles they claim could only have been decided by these mournful spirits. A captured bussengeist essence is a potent magical component. Rumor says a bussengeist's breath fans the forge fires of many cursed weapons, and that their power goes into crafting drums of panic and harps of discord.