#5 Samoa Joe

The "Samoan Submission Machine" Samoa Joe absolutely dominated in NXT, winning the NXT championship twice and having amazing matches again Kevin Owens, Shinsuke Nakamura, and Finn Balor. Joe has an amazing promo ability as well an intimidating look, both key factors in resulting in a main roster push.
When Joe finally debuted on the main roster, he blindsided Seth Rollins and attacked him, resulting in a feud between the two. Joe would later win a number 1 contender's match at Extreme Rules, where he would then face Brock Lesnar for the Universal Championship.
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Joe continued various championship pursuits throughout the rest of the debut year, looking dominant in all his matches. 2018 was when Samoa Joe truly began to shine when he was traded to Smackdown Live. Joe arrived in dominant fashion, obliterating Sin Cara in his Smackdown debut and defeating numerous other wrestlers.
Joe's biggest feud thus far was with AJ Styles, in which Joe won their first match via DQ, and Styles winning every other match. Despite not winning the WWE Championship from Styles, Joe was in the main event picture of Smackdown Live and one of its top heels. The feud, in particular, was one of WWE's more edgier storylines in recent years, creating more fan investment in the feud.
Joe is currently feuding with Jeff Hardy and continues to dominate Smackdown Live. I predict a great future for Joe on the main roster.