A green meteorite, codenamed "Green K" or the "Kansas Lode", was discovered embedded in the hull of a alien spacecraft that landed in Kansas in 1938; the green ore became the center of the top-secret Super-Soldier project. In the early 1940s, under the guidance of war profiteer Lex Luthor, Nazi scientists steal the spacecraft from the U.S. government and begin tests on the "mystery element". Seeking a weapon that can kill Super-Solder, Luthor harnessed the radiation of the Green K to power up Ultra-Metallo, a large-scale robot with a prominent swastika emblazoned on its chest. Luthor's motive for developing this weapon is the belief that Super-Solder would damage his profits by ending the war for the Allied Forces too quickly. Ultra-Metallo's "heart" of Green K emits radiation which only effects Super-Solider.
In March of 1942, Ultra-Metallo is rocketed toward Washington, D.C. with an explosive planted in its chest, programmed to detonate when it reaches the White House. Super-Soldier intercepts the Nazi war machine over the Atlantic Ocean; the two engage in a battle over an allied fleet, which ends with both combatants sinking to the bottom of the sea.
Decades later, Lex Luthor (now known as "Green Skull") and his HYDRA cartel rediscover Ulta-Metallo's remains, still in working condition. It attempts to fulfill its programming by once more attacking the White House. Super-Solder defeats the robot a second time with the help of the Judgement League Avengers.
- Super-Soldier #1
- The Appendix to the Handbook to the Marvel Universe - Amalgam Comics. Retrieved on 2007-10-10.