also I vastly underestimated the power of the eye shimmer

Also considering giving this a try - eyes as a separate object I shapekey to create expressions ahead of time, and then shrinkwrap onto the face (via a lattice modifier). Getting the eyelashes a little 3d pop while still basically working in 2d is a nice compromise.

So glad Blender continues to fuel my bad habit of refusing to learn another video editor

You can't sample the empty's coordinates directly but I think if you do some maths between the Object Coordinates of both the shaded object and the empty you can get there. Or maybe two empties you can spin around each other to form a sunlight direction

??? I believe you but that is a little baffling, but I guess it makes sense since they're not geometry

an Attribute node in the shader. But then you're just trading the tedium of drivers for adding a GN modifier to every single object so it's whatever.

I love playing with toon shading but people brave enough to recreate lighting from scratch are a world apart 🫡 and to be the voice of annoying inevitability, Geometry Nodes could help - it CAN use object info of external objects and store a vector per point, which you could access with [...]

I'm very much an intermediate at vector math, but would it make sense to have an empty, and then subtract your object coordinates from the empty's coordinates, and normalize, to get a vector pointing in the direction of the empty for every object?

I need to just spend an hour and analyze every particle effect in this, they are all so vivid and appealing