As for constructive criticism:

The 3D is a little too deep, as Arceus looks like two seperate beings.

Oppositely, the background is a little flat, as the stars look just as far away as the planet if 3D is on.
I'd recommend putting the planet on a different layer than the stars and void, to put emphasis on the planet. Beyond that, lessen the overall 3D effect, so it's more subtle.

That being said, Arceus looks great! The shading is well done, and it being more detailed than the background helps draw attention to the focus point of the piece. The pose and eyes create a certain sense of life and movement.

Hope this helps!