Bag of Stonethrowers folly.

A bag of 60 stones that has a picture of a young human boy throwing stones at another human boy.  Clearly written on the bag is the name Stonethrowers Folly above the picture.  This bag of 60 stones was created as a moral lesson giving tool.  If you throw a stone from this bag, as the stone strikes its target or enemy, then immediately a Goristo Demon appears behind the stonethrower and attacks whoever threw the stone.  The Goristo Demon does not attack anyone else, only the person who threw the stone.  If the Goristo kills the stonethrower it wanders off refusing to harm anyone else unless it is attacked.  The Goristo can be banished the same as any Demon if you dont want it wandering around.  This Bag of Stonethrowers Folly was created by a Red Wizard of Thay who did not like his servants children fighting for no good reason.  It became a proverb among his household "If you throw the first stone then you might not ever throw another!"  The Bag of Stonethrowers Folly worked as intended.  Despite being created quite a while in the past the bags keep turning up and are common items to be found.  I guess they can be moral lesson giving tools or could be used to summon Goristo Demons in undesirable places.  Just watch out behind you.  They only attack the stonethrowers.