You lost me at Triple H turning heel. That is a downright awful idea in my opinion. Firstly, I'm not denying Triple H is a fantastic heel, however Triple H's time in the spotlight is done. If Trips were to turn heel then they would have to focus a bunch of time on him otherwise what was the point? I'm just not a fan of focusing too much attention on Triple H, minus the short programs he works every now and again. Doing that while heel will just be ineffective, and your angle obviously plans to focus on Triple H being in the spotlight for quite some time (granted, not solely but still). I understand that this angle can be definitely used to put new guys over, which I've made no secret that I firmly believe that should be WWE's top priority, but none of those new guys seem to play any key factor. The biggest roles based off your brief description are HHH, Cena, Vince, and Punk, all of whom don't need to be put over any further.
Secondly, Triple H being behind The Shield's attack, and subsequently The Shield allying themselves with Triple H . . . really terrible. The Shield should work alone, hell they even recently said they have no allies. The second you pair Shield with someone else, have another mastermind behind them, have an ulterior motive for their attacks or change their motives you've completely killed what makes them special and interesting. What I love about The Shield is they truly feel like just about the three of them and the crusade against injustice. There is no way you can tie injustice into this without making them look entirely like hypocritical buffoons. For two reasons; one the obvious that they'll be allying with people who have most definitely done wrong and while Vince should definitely be on their target list, actually teaming with Trips is a no-no. I'd like it a lot better if they were just some third team messing up both sides when they see fit.
Thirdly, I don't just simply don't care for big stable feuds. Never have, never will but what makes this particularly bad is the length. This seems like it would be way to drawn out and I'm not a fan of it already, I don't think I'd last a month.
Fourthly, Cena's heel turn, why? Shock value? Heel turns/face turns done for pure shock value are crap in my opinion. Granted you only provided a base idea so if you actually have one please share because I can't think of one.
I'm not trying to be a dick or anything, that idea is just really unappealing to me.
