“Another magic of Blender and Grease Pencil. My favorite animated(Kung Fu Panda), my favorite software(Blender), and my favorite Tool(Grease Pencil), together.
I did this in Blender 2.82, everything painted by grease pencil.
I say it again, Grease Pencil is an endless potential for 2D artists.”
It seems to use this technique, which Maisam explained last week: