3: Aleister Black
The man formally known as Tommy End is probably the least expected and most shocking of all on this list because he's still in NXT. But WWE has introduced NXT superstars in the Royal Rumble match before like Rusev in 2014 Rumble and Tye Dillinger in 2017 and if they do it again this year, Black is more than ready to make his main roster debut.
Black's match with The Velveteen Dream at NXT TakeOver: War Games was Match Of The Year worthy. Aleister Black is already a force to reckoned with and still undefeated in NXT singles competition, so why not carry that record to the main roster?
If Black won the Royal Rumble match and faced Brock Lesnar for the Universal Championship there could be a big story there. Black's martial arts style against Lesnar's MMA style would be a treat to watch. Both Superstars were highly protected in 2017 and Black's undefeated streak vs Brock's Universal Title could make a pretty good storyline.