Answer:
A precious gift, yet it has no end, no beginning, and nothing in the middle.
What goes up but never comes down?
What loses its head every morning only to get it back every night?
They are the group who manages the winged engines of war.
I am not alive, though I never die, to no one I've ever told a lie, today I can be god's warrior, and serve him with no horror, but tomorrow I might be devil's knight, for I am what ends the light.
It is something you will never see again.