Riddle me this....

[fbd]

1, Voiceless it cries,
wingless flutters,
toothless bites,
mouthless mutters.

2, It cannot be heard, cannot be felt
cannot be seen, cannot be smelt
it lies behind stars and under hills,
and empty holes it fills
it comes first and follows after, ends life, kills laughter

3, This thing all things devours,
Birds, beasts trees flowers,
gnaws iron, bites steel,
grinds hard stones to meal
slays kings, ruins towns,
and beats high mountains down

and as a hint... 4, "What do I have in my pocket?"

wind, dark, time, a ring