Agora que o filme foi lançado, sabemos quem é esse personagem.
Este personagem é
the Vision, played by Paul Bettany
Nos quadrinhos, a relação deles com o Ultron é que
Vision was created by Ultron to prove that he could create life as well (Ultron himself being a synthetic lifeform). Vision is an android, and speculation suggests that it may be a spinoff of JARVIS come to the Avengers's aid.
No filme,
Vision’s body is created by Ultron as a final stage of his evolution; a final body for him. The body is created as a combination of genetic material and Vibranium. However, before Ultron can fully upload his mind into the body, it is stolen by the Avengers, and Stark and Banner load it with a modified version of JARVIS as a consciousness.