#3 Rusev

Rusev's career in WWE has been bizarre, to say the least.
Debuting on the main roster the night after WrestleMania 30, the Bulgarian Brute dominated for an entire year, until he came up against Big Match John.
Suffering his first loss at WrestleMania 31, Rusev has received stop-start pushes by the company, and despite being popular with the fans, has never received a run as WWE Champion.
You can see why the Bulgarian could be frustrated, with reports circulating that the former US Champion is looking to leave in the near future.
A valuable asset to the company, it would be bad for WWE to lose him, and could appease him with a match against Cena at WrestleMania.
That said, would the WWE allow the Bulgarian lose to Cena, twice, on the biggest stage of them all?