Hello Eisenhower Jam,
The Distance Fade Cull, outputs a 1-dimensional value in range of [0; 1]. Additional info you might want to consider, the node will always return 1 if the object isn’t culled, and 0 if it is fully culled, and it will transition between those values once the cull distance threshold is passed. However this information is not available to the vertex shader (the part of the shader which can manipulate the vertices), as far as I understood and will always output the value 1 for this part of the shader.
You could use the camera position node and calculate the distance to it, and use that as the lerp alpha.
Hope that helps. Just let me know if you have any questions.
Regards,
Vecherka.