4. The Rock
Although the Rock's interference at this year's Royal Rumble infamously flopped - as fans immediately saw through the weak attempt to galvanise Roman Reigns' push - a return as the mystery partner at Night Of Champions would surely elicit a more positive response. Family is already a key theme in the feud, which has seen Ambrose and Reigns refer to one another as brothers, and Jimmy Uso (another real-life cousin of Roman's) brutalised by Braun Strowman. The Rock's appearance would therefore make quite a lot of sense, but the fact that he's one of the biggest stars in wrestling history could cast doubt on this possibility. Surely the WWE wouldn't have missed the opportunity to advertise his presence ahead of time, were he actually partaking in a match.