The Nerve of the Princess

Man do I write a lot about King Sombra! Anyway...
King Sombra has been captured, and locked away in Canterlot. Stubborn, evil, and angry, he refuses all help that he is offered, and is forced to the dungeons, locked under severe watch and paralyzed until further notice, by decree of Celestia herself. But she believes that the power of friendship can reform him, and puts Twilight up to the task. With the power of friendship and the Elements of Harmony on her side, there's no way she CAN'T do this!
Or can she?