Answer:
A single syllable do I claim black was my most famous name; Fetal to mortals here below thousands have I slain in a single blow.
I cannot be burned in fire or drowned in water. What am I?
Upon your lonely journey I accompany you, whether you travel through endless mountains or seas of blue. Wherever you go, I keep your place. Lost you're not, when I'm embraced. What am I?
I am drawn by everyone without pen or pencil
I run smoother than any rhyme I love to fall but cannot climb.
What do you purposefully put lots of in and on your body, but run away from when you encounter it outside?