How to get ribs rotated


I am using a surface to get some kind of ribs that have the surfaces shape.
Now I am trying to rotate the ribs at the middle by 20 degree. Like you can see in the last Screenshot.
Have you got an Idea, how to fix that?

It would be also great to get a smooth fading from having 0 degree in the front and then 20 in the end. But with all the steps in between.

Thank you very much :slight_smile: