I've been thinking and tinkering on this one for a while, adding as many MCU characters to the SDCC concept art for Age of Ultron. Now I felt like we got more than enough characters in the MCU, I definitely was holding off until the Defender premiered and we got good enough images of them. I was going to wait until Iron Fist got a costume and for a better picture of Captain Marvel (I may update this as time goes on) as well as add Cloak and Dagger when better action pictures become available. But with the recent announcement with X-Men and Fantastic Four returning I thought it best to post this before it gets really out of control. So I couldn't add every character I wanted. Really this reinforces why I'm okay with the TV and films not crossing over, it was tough to fit them all in one concept art let alone an actual narrative. It's also tough finding action shots, specially for the TV characters since there were a lot of high res resources and their fight scenes are pretty blurry frame by frame and lighting is almost never inline with the original concept art.
Even so I couldn't add every character so I had a set of standards that each character should reasonably meet. First: They are all superheroes. Second: All character must be based on a character from the comics (sorry Coulson). Third: Only Earth bound characters since Ultron is an Earth threat (so no Guardians). Fourth: Should have a costume, proto costume, or wardrobe that works as a distinct "outfit" for the character.
Character who originally appear in the Concept Art:
Character I have added (in no particular order)
Doctor Strange (Updated with better image)
Hopefully I didn't miss one. As I said I may update if better images become available. I would be willing to maybe add Cloak and Dagger or the Fantastic Four, but I'm drawing the line at the X-men, that's just way to many characters to fit in. It's tough not only finding or creating the right image, but finding a logical spot for them in here as well. Still, 22 characters added is pretty impressive.