Tower of the Hand

The prophecy Maggy the Frog gave Cersei has been much talked about lately and the debate over who the Valonqar is seems mostly to be Tyrion versus Jaime. Both are younger or little brothers of Cersei, however both seem overly obvious compared to our favorite little brother: the Hound. We know that Cersei is being tried for treason by the High Septon and that she has demanded trial by combat. Jaime has already thrown her request into the fire and Qyburn offers her "a champion no man can defeat". Assumedly this is the Frankenstein monster of what is leftover of Gregor Clegane. When the High Septon calls for a champion for the Sept, who better to emerge from the ranks of the Sparrows than Sandor who has been saved by the faith and is healing up at the Quiet Isle? (The horse Driftwood is actually Stranger and the large lame gravedigger is our faithful Dog) His story arc must include killing his brother and in doing so, sealing Cersei's fate. So by his hands she will wring from her neck when she is hanged.