I wrote this monster for the Lamentations ref book. But, sad face, it was rejected. So here, it’s yours:
Armor 12, Move 0′, 9 Hit Dice, 27hp, see text for attack information, Morale 12.
Brought into being by centuries of religious and political bigotry, scheming and murder, this window from Prague causes all who see through it to view the world with a jaundiced eye that looks askance.
Whenever a person looks from the room at a passerby outside, the Sinister Pane dredges up and projects all of the viewer’s negative thoughts and reactions onto the subject. “Look at that idiot.” “Cheap bastard.” “That is an ugly face.” “I hear he tortures animals.” “Bloody peasant!” Etc., etc. All that disdain, mistrust, envy and rumour – however slight or fleeting – are spewed upon the subject with the effect of a Bestow Curse spell as cast by a 9th Level Cleric. The subject is allowed a saving throw versus Magic.
These curses will be minor hamperings, hindrances and ailments to be sure, but eventually everyone in town will be afflicted with one. And the settlement itself will develop a dark reputation as more and more travelers to and through the area are affected.
And whenever a person outside looks through the window at someone inside, the viewer will be affected by a False Seeing spell as cast by a 9th Level Cleric. The viewer is allowed a saving throw versus Magic. If the saving throw is failed, everything about the person in the room will be seen in the worst possible light. Capable leaders become incompetent schemers, honest priests become depraved manipulators, conscientious merchants become conniving short-changers.
A creeping pall of misfortune and ill will spreads around the Sinister Pane’s aspect. The window is an artist. It relishes the slow twist of corruption it weaves through a community, pouring one person’s poison onto another, and his onto hers, and on and again, never ceasing. It’s willing to perpetrate its torment upon a town for decades if it will lead ultimately to an explosion of chaos, rage and violence. It experiences ecstatic joy the very moment someone is thrown through itself to die in the street below. That is precisely the event it works tirelessly toward.
If somehow the nature of the Sinister Pane is discovered and the window is attacked it will defend itself. Once per round it will lift a handful of minor curses from persons not present and – with this flow of fresh hate – smite one of its attackers with a Bestow Curse spell as cast by a 9th Level Cleric. Madness is a preferred instrument in these moments because bedlam ensues. By inflicting insanities the Sinister Pane can turn its attackers upon themselves. The target of the spell is allowed a saving throw versus Magic. Though it does adore an angry mob, the Pane will never resort to such heavy-handed display unless and until it is physically assaulted; it much prefers the slow-simmer of a subtle years-long game.
The Sinister Pane cannot be harmed by forces of nature. Fire, water, stone, wood, lightning, earthquakes, etc. cause it to no more than shiver in its frame.
It takes half damage from metal weapons but it suffers double damage from unarmoured strikes (i.e., bare-knuckle punches). Anyone hitting the Pane bare-handed takes damage to their fingers equal to what they cause the window.
The Sinister Pane can be destroyed instantly and forever by someone voluntarily and willingly self-defenestrating through it. This act of clear-minded self-sacrifice will also immediately lift all curses and wipe away all false seeings caused by the Pane.
If reduced to zero hit points the Pane will shatter. But unless destroyed by self-defenestration all its curses and false seeings will remain in effect and it will reform and relocate over the next 6d6 years.
[I also posted it here among a number of other people’s entries.]