#4 Kane
Back in the day when Kane debuted, he was feared by every wrestler on the roster but is currently reduced to the role of enhancement jobber for upcoming wrestlers. Kane has been completely underappreciated by the WWE and has never got a chance to showcase himself as a main-event star.
Even though he has been with the company for almost 25 years, he has participated only twice at WrestleMania with one of them being part of the Kick-off show (does not include battle royals and money in the bank matches).
Kane attacked John Cena during the latest episode of Raw when Cena called out the Undertaker. He is set to face Cena next week on Raw, even though Kane's future is uncertain, next week's match between him and Cena will be pretty interesting. Kane shares the spotlight with Chris Jericho with 9 losses at WrestleMania.