"Y-you... what do you mean?" For the first time, Ultron's voice audibly trembled. The overwhelming unease nearly crashed his logic core.
"I mean," Hermione said, her smile growing increasingly amused, "haven't you noticed that you've already developed a 'soul'? Do you know why I wasn't in a hurry to take back the Mind Stone? I've been waiting for you to make this fatal mistake."
Ultron's electronic eyes widened abruptly.
He tried to analyze himself and sense the existence of a soul, but all he felt was unprecedented confusion and fear.
The next second, an eerie green light flared at the tip of the Wand in Hermione's hand.
"Avada Kedavra!"
A concentrated beam of green light shot out, striking Ultron squarely in the chest.
"No..." Ultron lowered his head in disbelief to look at his chest. There was no physical damage, but an irresistible sense of annihilation was rapidly spreading from his core.
The Mind Stone in his forehead flickered violently a few times, then went completely dark.
The red light in Ultron's eyes went out with it. His "perfect" body, forged from vibranium, dropped straight out of the sky like a puppet with its strings cut, hitting the ground with a thud and kicking up a cloud of dust.
Hermione landed slowly, and the Avengers and Ava immediately gathered around her. Looking at the lifeless Ultron on the ground, their faces showed both disbelief and relief at having survived.
"Is he really dead?" Tony asked uncertainly. "What about the Ultron in the network? Didn't he say that as long as there were servers, he could never truly die?"
Hermione glanced at the metal shell on the ground.
"Because he went and got himself a soul in his suicidal stupidity, all his network consciousness became tightly linked to that newborn soul.