#1. Why he should: Revenge for his WWE Championship loss four years ago
WrestleMania isn't a place that holds great memories for Bray Wyatt, since the former WWE Champion lost the title to Randy Orton just four short years ago. Orton was initially part of The Wyatt Family until he won The Royal Rumble in 2017 and turned on his leader in order to challenge for his Championship.
Wyatt only held WWE's most prestigious Championship for a little over a month before he lost it to Orton. Then, when he was granted a rematch in a House of Horrors match at Payback, it wasn't for the title.
This means that four years after Wyatt initially lost the Championship to Orton, he still awaits a rematch for the title. This is just one of the frustrations that allowed Wyatt to manifest his issues into The Fiend in the first place.
Gaining some kind of closure regarding one of the biggest frustrations of his short career could be the beginning of bringing back the old Bray Wyatt.