Probably the simplest way would be to make the player consist of two objects, one invisible base for the 8-Direction behavior and one visible character graphic with Pin behavior. Use Pin to make sure the player stays with the base object at all times.
Now you can use an event such as,
If button E is not pressed -> Set Player angle to Base angle
This means that the player object will point in the same direction as the base unless E is being held down.