#4 Bobby Lashley
Bobby Lashley returned to the WWE on the Raw after Wrestlemania. Everyone expected big things from him upon his arrival but he was booked pretty badly. His feuds with Sami Zayn and Jinder Mahal damaged the image of Lashley. Making Lio Rush Lashley's manager was a perfect decision by the WWE.
This past week on Raw, Lashley turned heel by attacking Kevin Owens after their match ended and in the process, he made sure Owens won't be around. Lashley is a legit ass kicker and Lio Rush is a perfect manager who makes the fans hate Lashley. Lashley is a powerhouse and with his heel turn, he is a perfect contender for the Universal Championship.
Lashley picked up a victory over Reigns at Extreme Rules, and the two men had another match two weeks later over the number 1 contendership for the Universal Championship, which Roman Reigns won. Reigns and Bobby Lashley are currently 1-1 in terms of victories over one another, and a match between them makes a lot of sense.
A match between them would certainly be entertaining, and if Lashley wins the match it could establish him as a top heel on Monday Night Raw.