The battle is joined.

Bitter news from the front. King Varian Wyrnn is dead. Betrayed by Sylvanas and the Horde. Newly crowned King Anduin Wyrnn faces division among his forces, even as the Legion's attacks increase. The Illidari have joined the fight, and even now we scour Azeroth for demon incursions.
But even in the midst of invasion, the Horde must pay for their treachery. And when that time comes, I, Steppenwôlf will be there.