There are ruins, scattered about the world, and all are sealed with unbreakable locks.
When all of these locks suddenly open, what emerges?
A cave with weapons sunken into the walls, blades sticking out of the floor and ceiling, and so on. Possibly, any weapon used in it could be torn out of the hand and sink into the stone.
A man is arrested for mass murder and found to be insane. Piles of corpses were found on his property, neatly stacked torsos with the skin peeled off and the limbs removed. The man readily admits the work is his, though he claims he was only chopping down trees, removing their branches, debarking them, and then stacking them to season.
The man may have swung the axe but it was a Druid who caused the delusion. This Druid is still on the loose and likely to repeat the crime. In time he may get more creative in his "punishments."