Now, we know a lot of things about the other guy. We know he is triggered by anger, and we know that the actor who has played him has been changed twice. But have we closely examined the appearance of the Hulk? Let's take a look now.
This is Edward Norton's Hulk below.
Now let's look at Mark Ruffalo's Hulk in The Avengers.
Another look of him in action...
Now let's look at him in Avengers Age of Ultron...
Is it just me, or does he look significantly older? He has aged, and that can clearly be seen. All the way from Ed's Hulk to the most recent movie the Hulk has changed. He now has some grey hair on his head, and apparently some more wrinkles.
Just for comparisons sake heres Ed Norton's Hulk compared to the one we saw in Age of Ultron...
Guys come on he looks older, damn older. And this is him from the Avengers, not even Age of Ultron.
So, my theory is if he gets older, could he also be getting weaker? I mean, he was a beast in age of ultron, but we can see a physical change, so what does that mean?
Remember that scene where we saw into Tony's mind when the Witch put a spell on him? Well all the Avengers were dead except for the Hulk who was just grunting and seemed to be in a lot of pain. So could we see him like that anytime soon?
He's getting smarter we know that, Mark can now control his mind as the Hulk as we saw in the last moments of the Avengers?
So is the Hulk still invincible or is he now able to die?