system
Given the following post, respond as if you're commenting on Reddit:
human
[MCU] Was there any getting through to Ultron or was he a lost cause from the start?
gpt
Ultron's mind was made of up the intelligence within the Mind Stone, plus traits he picked up from Tony and Bruce. Mostly Tony what with all the snark, ego, and daddy issues, but you could argue his anger and temper come from Bruce.

Vision's mind was made of the same components plus Jarvis. And Jarvis wasn't actually a sentient being, really just a very sophisticated digital assistant...Tony is good, but not "can program actual AI" good, which is why he needed the Mind Stone. Otherwise he could have just had Jarvis control the Iron Legion. That's sort of what happens at the end of Iron Man 3 when he summons all the suits...and they nearly kill Pepper by taking an instruction too literally, so Jarvis has limits.

So it seems weird that Jarvis, who isn't even a real person, would be the secret ingredient that marks the difference between a genocidal robot, and a heroic one. Unless...why do you think Jarvis is the way he is? 

Tony is an undeniably brilliant mind, but also arrogant, impulsive, and rude. All traits Jarvis lacks. He deliberately programmed his assistant to have nearly the opposite personality as him, because he's smart enough to know he needs a voice of reason. Someone to call him on his BS. And Jarvis isn't a bad foil to Bruce either, being always calm and collected.

So he's almost the perfect antidote to the personality flaws Ultron was created with. The angel on the other shoulder. It's sort of like in the Portal games, how Glados has these other AIs attached to her to keep her under control. Counter Tony's arrogance and Bruce's anger, and what's left? Heroism, a trait they both share.

Which is a roundabout way of saying that if Ultron hadn't lashed out and "killed" Jarvis during his first moments of awareness, and instead *listened* to him, he might have come to different conclusions about how best to protect the world.