John Cena

John Cena is arguably the greatest WWE Superstar of all time.
He was a consistent draw at the top for over 10 years. He has won Money in the Bank. He has main evented 5 WrestleManias. He has won two Royal Rumble Matches. And he has won the small matter of 16 world championships, tying the two time WWE Hall of Famer, Ric Flair, for most world championships won.
The next logical step would be for John Cena to win number 17, thus breaking the record, and setting a new mark.
The logical place for such a history-making moment to take place would be at the showcase of immortals, WrestleMania.
And the logical way to get there would be for John Cena to win his third Royal Rumble match, tying fellow great, 'Stone Cold' Steve Austin for most Royal Rumble match victories.
Yes, Cena is allegedly filming a movie at that time, but wrestlers have often misled their fans in order to generate a greater surprise at their return (see Jericho, Chris).
Cena could conceivably challenge either Brock Lesnar or Daniel Bryan.
John Cena winning his 17th World Championship against the greatest in-ring performer of his generation? Box office.
John Cena winning his 17th World Championship against the most dominant champion of this era? Box office.
John Cena winning the 2019 Men's Royal Rumble match? Box office.