#1 Roman Reigns vs AJ Styles

One thing is very clear - Roman Reigns and AJ Styles are the two most protected active superstars in WWE right now. Ever since the Brand Split in 2016, WWE has somehow managed to keep their two top superstars apart, with AJ acting as the face of Smackdown and Reign as the 'Big Dog' on Raw.
With the speculations that WWE might be thinking of bringing Styles to Raw in exchange for Rollins to SmackDown, WWE has the perfect opportunity to finally have these two come face to face again.
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If the rumors are true, Reigns will leave WrestleMania with the Universal Title but, Styles will lose his title to Nakamura. If AJ indeed returns to Raw after 'Mania, a feud against the Big Dog over the Big Red Belt would indeed be 'Best for Business'.
Their previous rivalry, which also started right after WrestleMania 32, produced two of the finest wrestling matches of the year. AJ and Roman have a very good chemistry with each other, and WWE must utilize this to make Raw a must see show during the post 'Mania period. If AJ Styles is returning to Raw, then he must enter into a feud with Roman straightaway.