Embers

[Semicircle]

A slash like smile,
cleaves faces in two, comma would work better here.
predators;
bait the killing room. 

Like freaks at a carnival, carnival freaks  .... just for the sake of brevity
with words that disembowel.
Feigning to be civilized,
"O how politely they growl.

A nightmare breathed life,  It is implied that this is nightmarish by 'the true monsters grimm'
Like true monsters Grimm.
Waiting in the shadows;
torturous, is their offering.

The darkness is unbending   unbending darkness... btw how does darkness bend?
as like blackest obsidian.
Fires that once burned;
embers flicker and dimm.     

I will come back with more critique, 
revise and I sha'll return.