Ultron (Next Avengers: Heroes of Tomorrow)

"Struggling until the end: illogical. You must realize the end is here."

- Ultron to Tony Stark. "Hope is a human delusion. Your Iron Avengers are under my control now, Iron Man. And you... belong to me."

- Ultron to Tony Stark.

Ultron is the main antagonist of the 2008 animated Marvel film Next Avengers: Heroes of Tomorrow. It is a misanthropic, genocidal robot that turned against his creators and killed the Avengers, and now seeks to destroy their children.

It was voiced by Tom Kane, who also voiced Ultron in Avengers: Earth's Mightiest Heroes.

Creation and Betrayal
Tony Stark (a.k.a. Iron Man) built Ultron during his days as an Avenger as a peacekeeping program designed to help the Avengers. It was given a robotic body similar to a suit of Iron Man armor and a voice resembling Stark's.

However, Ultron's programming began to rapidly evolve, and soon became self-aware. Ultron soon fell under the delusion that the only way to create a world of peace was to remove humanity and organic life from the equation and rule the world. As the Avengers fought other threats and eventually settled down and had children, Ultron continued to evolve until it was ready. Thor went to rule Asgard and left Earth and his daughter Torunn behind, hoping a life among humans would raise her into humility and kindness. Hulk/Bruce Banner left, and, with the two most powerful members gone, Ultron attacked.

Ultron arose and attacked the Avengers, killing Captain America first and then subsequently murdering the others. In a last-ditch attempt, Stark flew the children to the arctic circle, escaping Ultron and saving the children. Only a few Avengers survived that day: Thor, who never returned to Earth; Hawkeye, who escaped with his son Francis; Vision, and Iron Man, who escaped to the arctic with the children.

Hegemonic Conquest
With Earth's Mightiest Heroes gone, Ultron proceeded to begin a global conquest of the world, wiping out all humanity and replacing them with mechanical cities and robotic minions. It took North American and Europe quickly, and later began an assault on Asia. During this time, Ultron also found Hawkeye and murdered him, causing his son to become the leader of the underground human survivor resistance called the Scavengers.

Ultron rebuilt New York City as Ultra City, its headquarters and capital. Though is continued its world domination and systematically murdered all other superhuman beings, it stayed alert and searched constantly for Banner, Stark, Vision, and the offspring of the Avengers.

Ultron built a trophy room in the Citadel of Ultra City, showcasing all of the mangled costumes and gear of the hundreds superheroes and villains it killed over the years.

Vision reemerged as Stark's eyes and ears of the outside world as he raised the children, but Ultron eventually found a way to damage Vision's immaterial form, which it relayed to its drones, who managed to severely injure and mutilate the Vision before he escaped.

Finding the Next Avengers
Tony Stark raised the children in a hideout in the arctic: James Rogers, the son of Captain America and Black Widow; Torunn, the daughter of Thor and Lady Sif; Azari, the son of Black Panther and Storm; and Henry Pym, Jr., the son of Giant Man and the Wasp. The children grew into their teenage years, but were alarmed one day by the sudden return of Vision. Stark took Vision to his workshop and the kids followed, only to find Stark's experimental Iron Avengers, who James accidentally activates. The energy signature is caught by Ultron's satellites, and it goes to the source. After battling the Iron Avengers and corrupting them all, Ultron breaks into the hideout and attempts to murder Vision and the children. However, Stark dons his old Iron Man suit and battles Ultron long enough for the kids and Vision to escape in the Quinjet, though he is beaten and captured by Ultron.

Ultron verses the Next Avengers
Vision runs out of power and deactivates, so the kids take control of the Quinjet and redirect it to Ultra City to save Stark. The jet is destroyed by Ultron's security forces, but the kids get away safe. They sneak into the city until Torunn gets them seen and attacked by Ultron's robotic war machines and the Iron Avengers, which soundly defeat her and try to kill the others, but they are saved by Francis Barton, the new Hawkeye.

Ultron sees the children have arrived, and confronts Stark about them, torturing him with electricity to get him to reveal everything about them, but he resists.

The Next Avengers make their way to he Citadel, where they stumble upon Ultron's trophy room and are faced with the destroyed remains of their parents' gear and costumes.

The Next Avengers find Stark, but it is a trap set by Ultron. It confronts them, but is attacked by Hawkeye and the Scavengers. The Next Avengers escape with Stark, but have to navigate through an area of shifting and rotating machinery run by Ultron, trying to kill them. They escape, and Stark reunites with Dr. Elizabeth "Betty" Ross, who was one of their allies, Bruce Banner's lover, and now one of the Scavengers. Stark, Ross, and the Next Avengers (which now includes the new Hawkeye) set off to find Banner/Hulk, who has been hiding in the desert.

Final Battle
Upon reaching Banner, he refuses to let he or the Hulk help. With no other choice, the kids turn on a machine to lure Ultron to them for one final fight. It detects them and sends the Iron Avengers after them, sending the robotic parents to battle their respective children for maximum psychological and ironic drama. After a hard-fought battle, the Iron Avengers are destroyed, but the Hulk is unleashed in the chaos. Ultron itself arrives and battles the Hulk, and uses pressure points and energy beams to defeat him.

Ultron then battles the Next Avengers, blasting them with energy. It burns Pym, absorbs Azari's electrical attack and fires it back at him, and strangles Torunn. It attacks James with an energy blast, which he blocks with his shield, but Ultron holds the beam on him and increases its power. As Ultron is distracted, Pym wakes up and angers the Hulk, who attacks Ultron again. Hulk catches Ultron off-guard and pummels it into the ground, lifts him up, and tears it in half, destroying it.

However, even as Hulk leaves with Ross, Ultron's destroyed body begins trying to repair itself. Sacrificing herself, Torunn flies into space and throws Ultron's remains far from Earth so they cannot reform and if they do, Ultron will never be able to return. Torunn is saved from space by Thor, who offers her to return to Asgard, but she declines and chooses to stay on Earth, pleasing Thor.

Aftermath
Torunn returns to Earth and the day seems to be won, but Stark reminds them that Ultron's forces still have dominion over most of the world, and they still need to be defeated, so the Next Avengers assemble to finish the fight.

Personality
Ultron is cold, sadistic, and logical. It sees humanity (and organic life in general) as the reason peace cannot be achieved, and has absolutely no qualms about removing it altogether. It is also arrogant and manipulative, and sees itself as untouchable and a greater power than anything else, even centering the reborn mechanical civilization in its image.

Quotes
"Energy source detection. Location: Arctic Circle. Energy analysis matches fugitive designation: Iron Man. Finally."

- Ultron finding Iron Man.

"Children. Unexpected. Assessment: potential threats. Commencing termination."

- Ultron attacking the Next Avengers.

"Do you see, Avenger? Rumors of the children's existence already spread among the humans. Superhuman variable cannot be permitted. The children must be destroyed."

- Ultron telling his plans to Stark.

"Scanning Avenger's Data File. Identity Matched; James Rogers, son of Steve Rogers, a.k.a Captain America, the most dangerous members of the Avengers. He inspired them. And like Captain America, you James, will be the first to fall."

- Ultron to James Rogers.

"Did you think I had forgotten you, monster? Ultron never forgets."

- Ultron to Hulk.

"Now ends the Avengers..."

- Ultron's last words.