5. The Hound is alive
Sandor Clegane, also known as The Hound, was always a strangely ambiguous figure. Uncompromisingly vicious and violent, he seemed resigned to the horrors of the Game of Thrones universe. Yet, he would occasionally show some heart and compassion for others. For instance, he rescued Sansa from rapists and protected Arya as they searched for her family. The Hound was mortally wounded by Brienne of Tarth in the season four finale and Arya left him for dead. But there’s no body, and if there’s no body, there’s no guarantee of death.
There’s a theory that The Hound is alive and living as a novice in a monastery on the Quiet Isle. Click here for all the evidence. This theory corresponds to actor Ian McShane’s spoilers earlier this year. Mcshane will play a, “priest in his 40s or 50s. A gruff ex-soldier who found religion, now a no-nonsense rural priest who ministers to the poor of the countryside. He’s a salt-of-the-earth man who has weathered many battles.” This fits the description of book character, Septon Meribald, who alleges to the Hound being alive.