Answer:
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.
They are two brothers. However much they run, they do not reach each other.
Barren location, infertile and dry; my name means "to leave", it's not heard to see why
What kind of room doesn't have physical walls?
I fly to any foreign parts assisted by my spreading wings. My body holds an hundred hearts Nay I will tell you stranger things when I am not in haste I ride and then I mend my pace anon.