#1 By winning the Royal Rumble 2020
Out of all the scenarios mentioned in this slideshow, this one seems to be the most likely. It's just a matter of time before Roman Reigns becomes champion again. That is why a Royal Rumble win could be in the works for the Big Dog.
This scenario seems more likely now as recently, Mr. Money in the Bank Brock Lesnar failed to cash in his contract on Seth at WWE Super Showdown - that could mean he is going to cash in on the WWE Champion, Kofi Kingston.
With FOX soon to be the new home to SmackDown, they would want the company's biggest draws pitted against each other at the Show of Shows, that is WrestleMania 36. So, if Brock wins the WWE Championship, there is a huge chance that Roman could win the Royal Rumble 2020 and set up a match against his arch-rival on the grandest stage of professional wrestling.