He uses Copic markers, apparently coveted by artists worldwide, but which few own because they happen to be pretty pricey, approximately $100 for a dozen. He carefully keeps them well-organized. His coloured pencils are also well-cared for.
Check out more of Sushant Rane's work here.
Apparently 3-D art is not all that uncommon. Don sent me this link:
and there are lots more videos of other 3-D artists on YouTube. You can also find 3-D art tutorials on YouTube. Isn't the internet wonderful!