#3 Shinsuke Nakamura

Shinsuke Nakamura made his WWE debut in 2016. He made his main roster debut in April 2017 on Smackdown Live. In the beginning, it looked like Shinsuke might become a top star in no time but with back to back losses against Jinder Mahal, he was pushed down the card.
Shinsuke then went on to win the Royal Rumble match of 2018 and unsuccessfully challenged AJ Styles for the WWE title on 4 different occasions.
Shinsuke turned heel during his feud with AJ Styles and it started looking like he would win the WWE title from AJ Styles at some point but those were just speculations. Shinsuke then went after the US title and won it at Extreme Rules.
Shinsuke’s heel turn has been entertaining so far and it looks like he will be a major upper mid-card player on Smackdown in the upcoming months.
At this point however, it seems like Shinsuke’s title chase earlier this year will be the closest he would get to the WWE title for a long time. Shinsuke is talented in the ring but there's a lot of room for improvement in other areas.
He is improving rapidly but he could be assigned a manager for the time-being, which would be quite helpful.
Becky Lynch has been challenged HERE.