Bump.. this is still a bug.
If you are having trouble breaking the shield, try to stand as far back as possible from Aerin so the straight line sun dash will end on top of him, without cancelling the dash. This seems to work. When Aerin shields on the middle pedestal in the pit, you can get a long enough straight line to end the dash on Aerin if you start the dash at the top of the ramp at the edge of the pit (the ramp that connects to the middle pedestal with a very small gap - dash will cross gap).
Good luck!
