Having scared their victim off the topmost tower the phantoms would descend on their corpse like ravenous vultures. They of course had no interest in the flesh, before the ghostly soul could depart they formed a cage around it like an empty rotating ball, blocking it from it's path to the afterlife, trapping it for eternity to roam the earth with them. It was a grisly death and an even worse fate.

By maria, December 12, 2013.

All day they played among the purple flowers
That lay like frozen flames upon the lawn;
Or dreamed within the shadows of the towers
Whose turret tops were painted as the dawn.
Bright was the garden; peace went everywhere
There was no breath of movement nor any sound
Save butterflies that clove the heavy air,
Or when the bright fruit dropped slowly to the ground.
Then the flowers drooped, from sliver thorns that tore;
Too soon the sun had died in amber smoke,
And frightened now but silent as before
The phantoms watched the garden change its cloak.
Great sable moths flew out, and one by one
The towers melted with the fallen sun.

By mikeb, December 19, 2012.

Found in futuria fantasia - The Phantoms, authored by Joseph E. Kellerman.