The mistborn trilogy

Follows the adventures of Vin, a street urchin who has mastered the power of a Mistborn, and Elend Venture, the young nobleman who loves her, after they dispatch the immortal Lord Ruler who has kept their people in slavery for over a thousand years and try to find a way to form a healthy new society, while battling armies, the return of the lethal mists, increasingly heavy ashfalls, and powerful earthquakes.