The Terminus Factor

The Terminus Factor was a five-part storyline that ran throughout specific Marvel Comics Annuals during the 1990 Winter season. Primarily an Avengers-centric story, "The Terminus Factor" centered around the return of the alien conqueror Terminus the Destroyer, his Deviant successor Jorro and the robotic Termini.

In this story arc, it was revealed that Terminus had seeded the core of the Earth with spores that were released onto the surface by a manned probe sent into a volcano. Iron Man became infected by the spores when he had to rescue the probe and subsequently was driven into a berserk rage. Captain America was able to save Iron Man by drawing him into a protracted battle in the cold mountain range. (The spores at that time required heat to stay viable.)