#4 The Undertaker (WrestleMania 31, 2015)
With the exception of a brief period of weakness from April 2014 through July 2014, Bray Wyatt had been a dominant force of terror for almost two years. Wyatt dropped his followers, Harper and Rowan, near the end of 2014 and became a singular force, seemingly stronger than he had ever been before.
He no longer had anybody to provide physical outside interference, but instead he amped up the psychological warfare, very similar to the way The Undertaker used to confound, confuse, bewilder and straight-up frighten his opponents. He seemed primed and ready to take over for the aging Undertaker as WWE's resident "face of fear".
Wyatt had his opportunity at WrestleMania 31 in April 2015. He called himself "The New Face of Fear" and tried to coax The Undertaker to respond, and finally, when he popped out of a casket that everyone assumed Undertaker would be inside of, The Deadman answered.
The Streak had already ended one year prior at the hands of Brock Lesnar, so it seemed very possible, if not entirely likely, that Wyatt would not only defeat The Undertaker, but possibly even end the long career of The Deadman. The Undertaker persevered, however, and defeated the much younger and stronger Wyatt. His body may have been breaking down, but his mind games were still superior.
Sadly for Wyatt, this marked the beginning of a downfall. He licked his wounds by going after Ryback, who at the time was easy prey. It wasn't so easy once the summer ended.