You have overcome the greatest challenge this world has ever faced and defeated the last of the Prime Evils. However, we are too late to save the Worldstone. Baal's destructive touch has corrupted it completely.
Given enough time, the Worldstone's energies will drain away and the barriers between the worlds will shatter -- the powers of Hell will flood into this...Sanctuary...and eradicate your people and everything you've labored to build.
Therefore, I must destroy the corrupted Worldstone before the powers of Hell take root. This act will change your world forever -- with consequences that even I cannot foresee. However, it is the only way to ensure mankind's survival.
Go now, mortal. I have opened a portal that will lead you to safety.
May the Eternal Light shine upon you and your descendants for what you've done this day. The continued survival of mankind is your legacy! Above all else, you have earned a rest from this endless battle.