Hmmm... it's all very messy, you've smudged, distorted, and erased the c4ds, and put them at lower opacities, and it all doesnt look good when put together. Try to place the c4ds/effects in a more... aesthetic (

) way, that looks good and has flow as well, since here the flow is distorted by the smudging and erasing. Also, voldie doesnt blend well into the bg, mainly around the right side of his face... blending was a huge problem for me sometime back, and I just kept practicing, so I can't give you advice on how to blend the render/stock generally... The lighting is nice, but it's all very flat, you should try dodge/burns and blurs/sharpens.
try working on some smaller canvases, and using less effects, it'll help with the messiness, and try to avoid smudging/erasing c4ds in this kinda style, as it doesnt look all that great. You could also try going for a simple look with the effects, just try to keep it less messy.
I like that you're trying something different though, keep experimenting.