So we're thinking 4-way or 3-way at Mania?
Bryan vs. Reigns vs. Brock?
Obviously the foreshadowing of "we can't even take this title shot away" pretty much guarantees Bryan winning and Reigns being re-added to the title match, right?
It also helps in that you can then have Bryan win the belt, Rollins win it via cash-in a day later and then transition into a Reigns vs. Rollins feud with Reigns finally getting the top spot at SummerSlam.
If Rollins is not in the match, I'd have Rusev beat Cena at Fast Lane and then have Rollins win over Rusev at Mania, he already did a number on Brock, if he adds Rusev to that list you have a monster of guy in Rollins that people really believe as a legit champion for Reigns to have to conquer.