The Hero of Ages by Brandon Sanderson
The Mistborn Vin released the power in the Well of Ascension even after the mist spirit that tried to help her and Sazed before had wounded Elend Venture so she would keep the power. The prophecies of the Hero of Ages claimed that a savior would one day find and then give up the power in the Well. Believing this to be the right thing, Vin released the power to save the world from the Deepness. But the prophecies were tampered with. A force named Ruin was trapped in the Well and in its desire to destroy the world it had altered the Terris prophecies so that the Hero will be tricked into releasing it. Elend was saved when Vin gave him a nugget of pure Allomancy which contained the power of Preservation, Ruin's opposite. It turned Elend into a Mistborn. Vin and Elend would have to find clues how to save the world from Ruin. The Lord Ruler had apparently prepared for such an event knowing he would one day be defeated. He had stored food and other supplies in various cities. Their ...