This poem definately lacks detail.
I suggest you elaborate a little more, i do not mind short poems, but each line, each word, each letter must give off the some aura as the whole poem.
Small poems are usually quite tight in meaning, but sometimes are ambigious.
Nevertheless, they must make sense!
Why demonic blade?
Why a boulder?
Why sad? Doesn't it hurt?
Tighten up the meaning.
I like the word 'scrape,' its probably the only word that fits fully into the style.