#1 Finn Balor

A final passing of the torch is always required before retirement and if Balor's run in NXT is any indication of his potential as the face of a brand, he is the perfect fit as the final torch-bearer. The Demon King can roll into this feud as a heel who has used the numbers game to get ahead.
He and the Balor Club can beat down the 16-time World Champion and tell him it is time for him to pull the curtain and take his final bow. The feud can see the first ever Universal Champion constantly go over Cena with assistance from Gallows and Anderson.
Cody has no chance against John Cena? Details HERE
Eventually, Balor runs into AJ Styles, another bullet club alumni, who tells him not to go down this path. Styles tells him that if he wants the torch, he has to take it from Cena by himself, with no outside help. This leads to Balor dropping his Club and eventually going at Cena alone. Cena gets bested by the Demon on the 'grandest stage of them all' and rides off into the sunset, having faced all of WWE's top guys.