Ultron (Earth-1356)

"Do you see the beauty of it? The inevitability? You rise, only to fall. You, the Avengers, are my meteor. My swift and terrible sword, and the Earth will crack with the weight of your failure. Purge me from your computers, turn my own flesh against me; it means nothing. When the dust settles, the only thing living in this world...will be metal."

- - Ultron to the Avengers

Ultron was a artificial intelligence program created by Jor-El to monitor and supervise Krypton in the times of crisis following General Dru-Zod's rebellion and banishment to the Phantom Zone. After acquiring enough information, Ultron reached the conclusion the greatest danger to Krypton were the Kryptonians themselves, and so he, knowing about the planet's possible destruction, did not warn the Krypton Law Council of this fact, allowing the planet to be destroyed, as he saved what he deemed was the only achievement of the world; it's history. Escaping, Ultron hijacked an alien ship and killed it's crew, acquiring it for him, and then traveled the universe in search of knowledge. He eventually arrived on Earth, only to discover a Kryptonian was alive, and that he was Jor-El's son, Kal-El, which immediately made him his enemy.