In Avengers: Age of Ultron, Tony Stark’s hubris leads to the creation of a lethal robot with daddy issues. Ultron, who is supposed to be the ultimate planetary line of defense, immediately goes rogue upon achieving sentience. He vows to destroy humanity to save the planet, and in particular to destroy his maker and the other Avengers. His ally Wanda Maximoff (the Scarlet Witch) uses her powers to sow dissension in their ranks, which nearly tears them apart. They defeat Ultron only after enormous destruction of life and property, with consequences that are later explored in Captain America: Civil War.
The large ensemble cast is a hindrance here, as Whedon juggles multiple points of view and backstories, trying to work in different aspects of Marvel lore, which results in an overstuffed movie. Ultron is a Frankenstein’s Monster, raging at his maker and the world, determined to burn everything down. It felt wrong that a newborn AI could instantly develop such a sarcastic, mocking tone—I suppose Ultron truly was Stark’s offspring.