#2 Brock Lesnar
WWE has always promoted Brock Lesnar as an enormous box-office attraction who comes whenever he wants and does what he wants to do.
The Beast is his own entity, and since the company is cleverly extracting that persona into his current storyline, there's a significant reason behind it.
Roman Reigns' official coronation to the top of the mountain could come at the expense of Lesnar's retirement from professional wrestling.
The Universal Champion is heavily rumored to leave the company after WrestleMania 34, and despite his contract running out in August, Brock could be putting all his focus to return to the Octagon during that time.
There's no denying that Brock Lesnar has been huge for the WWE but considering his lack of passion for this business, it's safe to say that the fans are quite uninterested in him now.
Roman Reigns versus Brock Lesnar is scheduled to happen on April 8th, 2018 at 'the Grandest Stage of them All' and since 'the Big Dog' will most probably beat Brock for the title, there's probably no way Lesnar will ever step foot in a WWE ring after this.