After Roman Reigns wins the WWE Championship at Survivor Series, Seth Rollins will be given his rematch at the December pay-per-view. This could even be something with a gimmick like a tables match so that Roman Reigns can win and retain the title without having to pin or make Rollins submit. While Rollins is down on himself for losing two matches back to back, The Authority helps him out by putting him in the Royal Rumble match. Which he will win. Roman Reigns will defend the title at the Royal Rumble against some throwaway heel. I'd like to say Bray Wyatt but they seem to be done feuding for now, but just don't let it be Big Show.
So now it's set: Roman Reigns vs. Seth Rollins. Rollins can finally get his redemption. But since The Authority loves Seth Rollins, they're going to put Roman Reigns through hell before Wrestlemania. This will include an Elimination Chamber title defense at the PPV between the Rumble and 'Mania. Throw whoever you want into this thing- Kevin Owens, Cesaro, Neville, Barrett, Orton, Mark Henry, whoever- you just need to make sure two people are in here with Roman Reigns: Sheamus and Dean Ambrose. This will allow Sheamus to be eliminated from the match, cash in his briefcase (because you can do that in the middle of a match), hit Roman Reigns with it and try to go for the pin only to be broken up by Dean Ambrose, who is still in the match. Ambrose pins Sheamus and he's gone. Ambrose pins Reigns against his better judgment and is your new WWE Champion heading into Wrestlemania.
This would actually really shake things up as the pay-per-view between Royal Rumble and Wrestlemania tends to be a given that the champion won't lose their title. Yet, this would open up the opportunity for Roman Reigns to envoke his rematch clause at Wrestlemania while Seth Rollins also would be in the match for winning the Royal Rumble. Shield Triple Threat. From there, well, I'll let WWE handle that. Now, some sort of scenario such as this can still be attained if Seth Rollins doesn't lose at Survivor Series but then Roman Reigns would have to win the Royal Rumble (ugh) and then Rollins would take the fall at Elimination Chamber to Dean Ambrose so it would still play out the same for Ambrose just everything from the Rumble on would switch the roles of Reigns and Rollins.
I'm not sure what other plans WWE would have for Wrestlemania other than a Shield Triple Threat and it would be kind of cool to see Seth Rollins to keep the title until Wrestlemania though it'd leave little room for Dean Ambrose to somehow get into the match if he didn't win the Rumble (or for Reigns if he didn't win the Rumble) but I really just don't want one of those Luger/Hart scenarios to play out again. So if WWE got there some other way, props to them, but I really think this could be the way to do it.