The second installment of the Breaking Dawn film gave fans horror in Alice's vision, all while making the most feared coven in the vampire world look /weak/, leaving out guards that would've improved their chances of winning.
Bella Swan was a Mary Sue from the start, as most heroines of young adult literature are. In the real world, the inevitable happens. Bad guys have power, and the people are often powerless. As biased as that is, it makes for better SLs. When people are brought so far down, demons take over until they can rise again.
Going with the canon people and power of the books and twisting it with the unfortunate events of that vision, we give you something unheard of, it's a story Untold and waiting to be written.
Afton of the Volturi felt free the moment Paul Lahote in wolf form ripped Chelsea's head off her shoulders. Frankly, so did the rest of the Volturi, yet something still kept them together... Caius (genderbent) had been planning for centuries, keeping his hands free from Aro, and now was her chance.
This was the war to end it all.
Afton's minor shielding ability went unoticed when the Denali sisters held Caius in a painful grasp, that it was easy for him to remove Tanya fron existence, and distract Kate long enough for Caius to kick her into Garrett who got another surprise shock.
With Athenodora having been friends with the Romanians, tensions eased in the battle field, but even she perished at the jaws of a wolf.
However, when Aro had met his demise, Renata, feeling vengeful from centuries at his side, was quick to avenge him. Her and a few guards managed to tackle Edward and Bella down, distracting Bella from shielding properly. Renata had removed her from existence, and Edward watched in horror. She, like Victoria before her, wanted him to experience the pain of a broken bond.
Fast forward to the present day. Edward and Alice are alive, as apathetic as Marcus was. Carlisle has held himself together because it's what Esme would have wanted. Rosalie and Emmett took the liberty of raising Renesmee away from the wolf pack, and the three currently reside in her hometown of Rochester, New York. Even Renesmee doesn't remember her birth parents anymore/ Jacob hasn't been the same since. Charlie and Sue, with knowledge of vampires and werewolves, cope together for the loss of their children. Kate and Garrett have split, while Eleazar and Carmen have relocated to Canada. Maria met up with Peter and removed Charlotte from the picture.
Caius along with the Romanians have formed a new coven, and continue to reside in Volterra. Renata and Afton were nomadic and romantic for years together, beside her relatives Makenna and Charles, and before returning to Volterra to rekindle their guardship.