Megiddo was a settlement located in an unidentified distant planet where the Ultimos originated. It was established by Stilt-Man, who once settled in this planet to escape his previous life and build something good for himself to lead. Using a teleportation beam, Day secretly abducted people from all over the universe to this planet. Under the pretense that the same thing had inexplicably happened to him, Stilt-Man rallied these castaways in building a colony where they could embrace a humble lifestyle and appreciate that they cut ties to any past responsibilities and expectations for themselves.
Due to his infamy for his past as a super villain, Day ran Megiddo from the shadows, with the Kree soldier Yar serving as the public face. Another of Megiddo's inhabitants was the Canadian armored hero Avro-X, who became the leader of the colony patrol. The community used the scattered fragments of innert Ultimos for energy to power their turbines and generators. It relied on farming and it also possessed a well for water.
One of the key elements of Stilt-Man's plan for Megiddo was that he had also secretly learned to reprogram and remotely control the Ultimos. He had Ultimos regularly attack Megiddo to establish them as a constant looming threat so the Megiddans could bond over survival. After hearing an S.O.S. signal from a spaceship piloted by Iron Man when the hero was pursuing the power-hungry android Korvac, Stilt-Man decided to abduct Stark to show the fruit of his labor. Iron Man was initially captivated by the Meigddan's simple lifestyle as well as Stilt-Man's apparent change of heart, and he helped the colony take down one of the Ultimos that attacked the colony, although Yar died in the process.
The constant threat of the Ultimos prompted Stark to look into them, and he ultimately discovered that Day was remotely controlling the killer robots. Together with Avro-X, Iron Man confronted and defeated Stilt-Man. Afterward, the Megiddans took Wilbur away to punish him. In the aftermath of Stilt-Man's ruse being exposed, the Living Tribunal sought Iron Man to continue his pursuit of Korvac, and the hero asked him in exchange to return everyone on Megidda home.