I love the image concept, half Cloud, half Sephiroth, symbolizing that one is not complete without the other. But, like Tales said.. with this only being a small crop of the original, the difference needs to made more obvious. Maybe you could add like a small thin line of outer glow.. with pixie dust pouring from the bottom and top.
The BG could be just a little bit lighter too, not too much though, would take away from the dark feeling the sig eminates.
7/10