Tutorial For This Large Art?

Well just the transitions of lighting scream Illy too me,even with cartoon materials the lighting would look more realistic if it was done with C4D imo(or any other 3d modeling program),and it's not that hard to make things look 3D.Like I said earlier though he could have used a C4D model as a base, it would probably make the job a lot easier since it's just vectoring over something instead of doing it from scratch.