#4 Ethan Carter III

EC3 was to TNA what John Cena was for WWE. EC3 was a star in that promotion and made a name for himself cutting excellent promos. Similarly to Cena, EC3 did not have out-of-the-world wrestling skills but still rose to the top of the mountain.
EC3 and John Cena need to feud simply for the sake of some excellent promos which will take place. EC3 is currently being presented as a superstar who doesn't talk much, which is a polar opposite of the narcissistic gimmick he had previously.
Cody Rhodes' uncle is a WWE Hall of Famer. More details HERE.
EC3 is a great talent for the future, and if WWE intends to push the superstar, this is the time!
#3 Aleister Black

Yet another NXT upstart who made his debut on Monday Night RAW. Black stands out from the crowd of NXT imports with his dark and intriguing gimmick.
Black is a talent who can create magic in the ring, and is one of the deadliest strikers in the business. Black vs Cena would be a dream matchup for the WWE Universe