It's ok, it's kind of of obvious to me that you've just googled "pentagram" "blood drops vector" and "skull" and picked some of the first things that pop up (hopefully they're free for commercial use) and popped them on a square canvas, but montage skills take time to develop and that's what graphic designers are for.
I will however remind you that chapter covers are 300x300px on the site: that mini skull in the corner is just going to be a fuzzy grey dot at that size, some people won't be able to make out what it is, nevermind that there's also a candle and a rose and greenery. Think thumbnail, not book cover, very little detail is required.
