#1 Roman Reigns vs. The Fiend?

Roman Reigns has recently made a huge comeback to WWE when he interrupted the match between The Fiend and Braun Strowman at SummerSlam. He then went on to win the WWE Universal Championship at Payback a week later. At Payback, Reigns ended The Fiend's time as champion at a considerably short seven days.
A rivalry between Reigns and The Fiend seems like one of the next logical steps for the pair. Although Reigns won the championship at Payback, The Fiend wasn't the star who took the pinfall, meaning Reigns hasn't defeated him yet.
As well as this, Reigns is now a Paul Heyman guy and the latest character to appear in the Firefly Funhouse, Wobbly Walrus, seems to be styled on the manager.
There is also a history between the two. In 2014, the pair crossed paths when The Wyatt Family took on The Shield at Elimination Chamber. The rivalry was an unusual one, as at the time both factions were heels.
At the moment, Reigns is being built as a heel and The Fiend appears to now be a face following his feud with Braun Strowman. Pitting the pair against one another has the potential to cement Reigns in his new role.