4. A Roman Reigns Feud
Cena has worked against nearly everyone on the roster, but one big, fresh opponent for him in 2016 is Roman Reigns. The two men are in the same sort of spot, both being obvious WWE Title contenders/potential champions. That inevitably puts them on a collision course. It is a classic story of the new lion testing himself out against the leader of the pack. SummerSlam 2016 looks like a fitting occasion for such a contest, and it would likely be face against face. Both men generate strong reactions, both negative and positive, so it would be a really interesting dynamic. The Brooklyn fans are sure to have fun with that one. Indeed, Cena could be key in helping to "make" Reigns. Putting him over would be a Hogan/Warrior WrestleMania VI moment, one in which Cena could come off looking really good despite tasting defeat. It has the potential to be a match of the year and could well prove to be a significant moment in WWE history.