The Nord is shown at the start of the trailer fighting a zombie werewolf. At the end of the trailer, we see one of the werewolves burst out of the ground in an attempt to flee, only to be dragged back under by the Nord, who climbs out a second later.
The Breton commander who pulls off acrobatic feats and kills a squad of solders in a manner that would make Altair gush.
The Altmer commando treating the gigantic melee and siege she's navigating through with appropriate Altmer disdain. She'll need more than a nigh-unkillable Nord badass and a spinning top of death-dealing Breton in her way to properly inconvenience her...
The Arrival Trailer. showing the three leaders from the Alliance trailer having to fight a platoon of dremora. It shows how much of a threat that they'll be, because the Breton ends up possessed and attacking the Imperial City with a army of undead while the Nord and Altmer barely escape with their lives.
This trailer really belongs to the Altmer Mage who holds her own against well over a dozen Dremora using her sword and truly impressive magical skills and she's the one who destroys the Dremora portal single handed. The Nord also puts in an impressive showing by looking at the biggest enemy in the room (a 20 foot tall flesh monster), then charging right at him and actually managing to hold the advantage for the first half of the fight until the addition of a few tiny Scamps turns it less in his favor. The Breton sadly gets beaten by a Dremora wizard before getting turned into a zombie. The video ends with the Nord digging up the unconscious Altmer from the rubble and carrying her after the Breton.