Rotate subdivided plane with x+y locked I’m wrapping my head around one issue that seems pretty simple:
Cube with loop cut.

Picture: I want to rotate the top planes and keep their x/y coordinates.


I don’t want to do it with proportional editing for multiple reasons


I want to start out with a flat plane.

Additional: Is there a command to align edges/vertices between two endpoints?
Use the Shear Transform from the Mesh > Transforms menu. I see you are still in 2.79. I would really recommend updating, because the Shear Tool in 2.80, which does the same thing is much more intuitive to use.