Here's how I see it happening, Cena loses a highly competitive match which brings Lesnar's invincibility down into reality, then Rollins comes to cash in on a beat down Lesnar. Triple H comes out and says Lesnar lay down for Seth to win the belt. The match is about to start when Ambrose runs in from the crowd attacking Seth, Brock leaves the ring with the belt. Meanwhile, Sheamus loses his belt to Cesaro.
On the Raws leading to HiaC you have Rollins/Ambrose feuding, Sheamus using his rematch on Cesaro. And Trips announces Lesnar's HiaC opponent, the worlds largest athlete the Big Show! I know none of us care for it, but it makes sense. Show is a face, he's been booked strong recently and he'll always be a threat due to his size.
HiaC:
Lesnar(c) v Big Show = Lesnar
Rollins v Ambrose = Ambrose
Cesaro(c) v Sheamus = Cesaro (but have Sheamus look really good)
On the build up to Survivor Series have Orton say he wants his shot, that he never got it because of Triple H and he's going to get it regardless. Continue the Rollins Ambrose feud. And start pushing Sheamus, feeding him higher level guys, give him promo time anything it takes.
SS:
Lesnar(c) v Orton = Lesnar in a close contest
Rollins v Ambrose = Ambrose again (Rollins won like every encounter before Ambrose left, so he needs a few)
Now going into TLC you have a tournament, say that Brock can't compete at TLC due to his contract and that the new year will allow him to fight again. So a tournament leading into and through TLC for number 1 contendership. You have 16 guys competing(I see it as Sheamus, Orton, Big Show, Cena, Jericho[one night return], Cesaro, Bray, Swagger, Ziggler, Miz, Rollins, Kane, Ambrose, Triple H, someone else, a returning Reigns.
Round 1: Sheamus v. Miz = Sheamus, Orton v Jericho = Orton, Big Show v Rollins = Rollins, Cena v Cesaro = Cena, Bray v Swagger = Bray, Ambrose v Triple H = Triple H(Rollins interferes), Ziggler v Someone else = Ziggler, Kane's out in the ring and Reigns is announced as the final participant(this way they can gauge the reaction and see if he's still over) = Reigns
Round 2: Sheamus v Triple H = Sheamus(I expect heavy interference from Kane but Sheamus dominates), Orton v Cena = Cena(they pretty much have to face off, sorry), Rollins v Triple H= Rollins(Trips lays down for Rollins), Bray v Reigns = Reigns(of course give Bray a fighting chance though)
Round 3: Sheamus v Cena = Sheamus(Sheamus just happens to win the match), Rollins v Reigns =Rollins(this would be somewhat of closure to the Reigns being injured by Rollins angle but it also gives the Authority the power to screw him leading to Mania).
Final Round: Sheamus v Rollins = Sheamus due to interference from Ambrose early on. Sheamus is number 1 contender, he beats:Miz, Triple H, Cena and Rollins, obviously looking pretty dominant so he can take on Lesnar at Royal Rumble.
TLC:
Rollins v Ambrose for the briefcase = Rollins(No Kane Interference, make this win mean something huge for Rollins).
RR:
Lesnar v Sheamus = Lesnar(lets be real, no one expects Sheamus to win but with this level of build up he'd be a believable opponent)
Reigns v Rollins = Reigns(this just settles the beef between them)
Ambrose v Kane = Ambrose(basically it's retribution for all the interference he's done, hopefully it writes him off screen for a couple months and it helps Ambrose rebound from Rollins)
Royal Rumble: I ask for 2 things, Bryan's return to a huge pop and the Rock comes back, if not there's ways around Rock but Bryan needs to come back now...anyway Bryan wins and we need a Reigns/Rock staredown disrupted by Orton
Build up to EC features Sheamus trying to regain some believability as a main eventer, Reigns turns his attention to HHH being as they still haven't fought while Ambrose turns his attention to Orton, Bryan targets Heyman
EC:
Ambrose v Orton = Orton (a shocking win and this is basically to prolong this feud to Mania)
Reigns v Trips = Reigns (by now Reigns should be regaining his momentum and this match will help big time)
WM:
Reigns v Rock = Reigns(Rock wants to put him over right so why not?)
Ambrose v Orton = Ambrose(I feel bad for Orton but this pretty much needs to happen)
Bryan v Lesnar = Bryan(second big year in a row, this rub would be going to Reigns but o well)
Other big matches xD
Anyway at HiaC Lesnar can fight Big Show