Building a Rotator from scratch

Please note that I didn't figure out how to make this at all. I had no idea how to make a rotator. I had to look at the Custom Rotator material function to figure out how to do this.

I just noticed that the TexCoord and pivot point are in the wrong places. (they should be swapped) This obviously wouldn't make a difference if it's rotating around the center but it won't offset back to the right place for any other pivot point.