#3. Former two-time WWE Champion Seth Rollins
Seth Rollins and Edge have quite the history on WWE TV since The Rated-R Superstar was used in one of The Messiah's plots on RAW almost six years ago. Edge hasn't got his revenge against Rollins as of yet.
Rollins threatened to break Edge's neck if The Authority were not reinstated, which then forced John Cena to make the rough decision back in 2014. At the time, Edge wasn't expected to step back in the ring again, but now that The Rated-R Superstar is cleared to return to the ring and Rollins could return in The Royal Rumble, it's perfect timing for both of them to confront each other.
Of course, Edge is on RAW, and Seth Rollins is on SmackDown. But there is nothing stopping these two men from having a back and forth during the Royal Rumble match.
This feud may not take place at present, but it could occur in the future and include Beth Phoenix and Becky Lynch if WWE wants the women to be added. A tease for a future feud in the Royal Rumble could be enough to excite the WWE Universe, especially if Edge is the man who eliminates Rollins.