Very nice, no other words come.
The blood-splattered background adds just the perfect touch the picture needed. Said background also eliminates negative white space, every critic's biggest pet peeve. The outfit Nicholas is wearing looks very "evil," and that helps too.
Your style is very nice. Cartoon drawings like this one and pixel art are my two favorite styles.
This is just a random little comment, totally unimportant to the review: I wonder what he is reading? The title's on the other cover, so...yeah.
This is another pet peeve of mine, a small one, but one nonetheless (And I need an excuse to not rate this 10/10). Blood in a picture shouldn't automatically make it M-rated...should it?
It has occurred to me I've spent entirely too much time choosing my words for typing this review. You have earned yourself 9/10, and since I know this has probably taken you so much effort and time, and I appreciate that, I'll round up to a 5/5.
This has been the opinion of no one. Really.