With her 'Impossible Girl' mystery solved, Clara was allowed to flesh out as a character and over the course of her final two episodes with the Eleventh Doctor we saw just that. Having saved all his incarnations it would have been simple enough for her to fade into the background somewhat, travelling with the Doctor but not really helping him. Moffat chose not to do that; in his follow-up adventure, the 50th anniversary special Day Of The Doctor, we saw Clara make another arguably more momentous contribution to the Doctors (plural) and all of Gallifrey. With the War, Tenth and Eleventh Doctors resigned to the fate and ready to push the button, activating the Moment, Clara steps forward and convinces them all to find another way. Just like the Twelfth Doctor, she is the conscience on the Doctor's shoulder and because of her it allows the Doctors to remain heroes.