This is one of the impossible figures that I myself feel works a bit better as just linework. This might be because the figure looks bent with the gradients, so the lines only version looks more clean, which is without saying really. Still, colors give volume and makes things look nice.
Both the tower and the wings transform from one end to the other. What was in front goes behind, what was a solid turns into air, surfaces from different structures melt into a new single one.