Answer:
My life can be measured in hours, I serve by being devoured. Thin, I am quick. Fat, I am slow. Wind is my foe.
Searing 'cross the pitch-black skies, I scream in celebration, Yet moments later, my outburst through, I am naught but imagination.
An iron horse with a flaxen tail. The faster the horse runs, the shorter his tail becomes.
I went to the woods and got it, when i got it didn’t want it, looked for it, couldn’t find it so I took it home.
My first is in blood and also in battle. My second is in acorn, oak, and apple. My third and fourth are both the same. In the center of sorrow and twice in refrain. My fifth starts eternity ending here. My last is the first of last, Oh Dear.
If it’s information you seek, come and see me. If it’s pairs of letters you need, I have consecutively three. What am I?