User blog comment:VampiresAndWerewolfsareAwesomeAsHell23/Seth Clearwater's Death/@comment-5666811-20121122202337/@comment-66.138.59.115-20130407003708

Alice wasn't evil, she actually saved them (Cullen-side). By showing Aro his future if he decided to attack, it stopped him because he knew he wouldn't survive it.

The battle served two purposes: I just mentioned the one above. The other was just a publicity stunt to get more people in the theaters and freak people out. I know when I first saw the battle scene... I kept thinking, this is impossible, the books not like that!