Have you seen the Lordaeron cinematics? The tide turns.
https://www.youtube.com/watch?v=x7O2d0FO3_M and https://www.youtube.com/watch?v=mVlZzJngUKE
The girl has some power. She seems more powerfull than Khadgar and Thalyssra combined. I mean ... she is raid boss powerfull.
This would be a great way to give the Horde players some satisfaction for killing Garrosh and loosing 3 warchiefs in a row.
This much power could possibly overwhelm her, right?
She will eventually GO NUTS!