The patronus is willed to take the form of a sphere when Harry leads the Aurors to rescue Draco. And, yes, it might protect from AKs and from Voldie, but the Death Eaters have been instructed to attack Harry with a wide variety of curses.
The patronus is willed to take the form of a sphere when Harry leads the Aurors to rescue Draco. And, yes, it might protect from AKs and from Voldie, but the Death Eaters have been instructed to attack Harry with a wide variety of curses.