I am kind of in love with the fates, and the possibilities they open for modeling scripts for NPC behavior and other things that happen.  I was messing around with them and realized you could do things more complicated than just the decline in health and strength of a thing.  For instance something like:

We will boil out of our hiding place and bedevil the region.
We will withdraw for now, but remember the faces of those who harmed us.
Those who survive will come for you wherever you are.
The last of us will hound you to the grave.