I am standing on a perfect unit sphere. I can describe any point on the surface in terms of longitude and latitude because I arbitrarily marked a "North Pole" and "Prime Meridian" on the surface.
Suppose I select a non-polar point and turn to face a selected direction. If I were to walk in that direction following a great circle route for some angular distance, where would I arrive? (Walking 360° would take me back to where I started.)
For example, "Starting at 53°N 3°E, facing 80° clockwise from North, where would I arrive if I traveled 200° along this great circle?"
Note: I excluded the poles because facing in a particular direction is ambiguous. I am happy if a simpler formula doesn't work at these two points and I have to take a step to the left before calculating.