Joffrey hasnt been dead long, but Tywin is already preparing his other grandson for the challenges of ruling. While looking over Joffreys body with Cersei in the sept, Tywin asks Tommen which qualities a good king must possess. Tommen lists holiness, justice and strength, but Tywin lists examples of how previous kings were undone by those traits. Tommen realizes that wisdom is what these kings lacked and is the most important quality for a king. Tywin points out that a wise king must heed the advice of his counselors, and that Joffrey was not a wise king, otherwise he might still be living. As they leave the sept, Tywin asks whether someones giving him the birds and the bees talk, since Tommen will eventually have to continue the family line. Its not an exaggeration to say that almost anybody would be a better king than Joffrey. Tommen may be young, but hes already looking to be a better ruler than his brother would ever have been. Tywin may not be the warmest character on the show, but hes knowledgeable about being an effective ruler, so Tommen would be wise to listen to him. Still, despite Tommens royal promotion, its unlikely hell have any real power until he becomes an adult. Expect Tywin and Cersei to still be calling the shots.