Answer:
I march before armies, a thousand salute me. My fall can bring victory, but no one would shoot me. The wind is my lover, one-legged am I. Name me and see me at home in the sky.
To unravel me you need a simple key, no key that was made by locksmith's hand. But a key that only I will understand.
What surrounds the world, yet dwells within a thimble?
My first is equality; my second is inferiority; my whole is superiority.
I run through hills. I veer around mountains. I leap over rivers. And crawl through the forests. Step out your door to find me.
What do you purposefully put lots of in and on your body, but run away from when you encounter it outside?