I am making skyboxes for a game, and would like to prototype the skyboxes' rotation angle in Blender. I made a simple vertical mesh line that represents the rotation axis of the skybox, and I would like to be able to rotate the skybox along the mesh line's local Z axis, no matter how I rotate the mesh line itself.
Here you can see if I rotate the mesh line on the X axis, and make a new custom orientation from it, the skybox rotates around the mesh line as expected, but I would like this to be dynamic, so I can animate the skybox rotating, and when I rotate the mesh line, the skybox rotation adapts accordingly.