You came forward with a plan before the Council of Light. You spoke with passion, and they listened. "To defeat the Horde, one must combat it from a less anticipated position."

So it was agreed that you would be sent down into a mortals body, at the Hordes next targeted world. The Horde would not expect this.

A mortal in need of redemption was choosen for you. So good would come out of the plan no matter the result. The mortal is finally in range, so you must hurry...