Random C4D placement, lack of flow. Doesn't appear that grids were used either.
Instead of the 'engulfed' appearance you're aiming for, I see just a bunch of C4D's place above and behind him. Blending needs improvement.
Good effort though. What's the coloured version like?
C4d's look a bit overpowering on the focal, and a little blurry to the far right. Good work
It's best sometimes to not blur at all if you don't know exactly where to do it. Also, a good way to fix the C4D obstruction would be by moving some of them behind the render, particularly the ones directly in front of it.