This a breakdown with some theories of the second trailer for Avengers: Age of Ultron, hitting theaters on May 1 worldwide (Not in chronological order).
Now after watching that, your minds were probably blown away by all the action and suspense. But did you notice the hidden messages or meanings throughout the video?
Captain America's New Suit
In the picture above, you can examine the 'Avengers Initiative' logo on his sleeve instead of S.H.I.E.L.D. since it's gone.
Wanda and Pietro (a.ka. Scarlet Witch and Quicksilver)
In the gif, it shows Wanda and Pietro in a riot of people screaming at something or someone. This scene was in the first trailer but something in the second caught my eye.
In this scene is a woman who is running to get somewhere but falls down in front of others. She has similar clothes on that Wanda has in the previous gif. and she looks like that might be her.
These two scenes have a similar setting with the smoke and some of the debris, so these two clips could be tied together. The idea is that the Avengers could try to save people by letting them go on a ship, but they had to leave early so many are rushing to get there. The people in the riot could've have been left to die including Wanda and Pietro. Wanda might have fallen and Pietro went to help and they both missed their flight to safety.
Ultron's Blast of Energy
In this trailer, we now know that Ultron has the power to generate a red blast of energy from his hands to use as a weapon. But this blast also looks similar to Scarlet Witch's powers. Perhaps they share the same energy?
I'm going to tear you apart from the inside.
Hulk's Red Eyes
During the end of the Hulkbuster fight with the Hulk and Iron Man, the Hulk turns around and you don't see his green eyes; there's only red. Now, I don't think this is just irritation and a the cause of an infection, he might be under the control of Scarlet Witch. She could be controlling all of his actions or is simply showing him a terrible vision which triggered the fight with Iron Man.
From all my guesses and ideas of who this character might be, the best one is Ulysses Klaw. Since, the rumor went around about Black Panther making an appearance in the movie, it would make perfect sense for this character to show up as one of his enemies.
Natasha Romanoff's Past
Natasha's past could've been recalled again because of a vision from Scarlet Witch or even just to weaken her mind. But her memories certainly are dark.
In the earlier comics, she was an orphan and was placed into Department X where they would brainwash younger girls like her and turn them into spies for agencies. This scene might have been part of the brainwashing process or surgery. Either way, it's definitely shocking.