"Iron Man" appears to be about a man who travels to the future and witnesses the Apocalypse. On his way back, he is caught in Earth's magnetic field, and turned to steel. When he comes back, he tries to warn the people about the Apocalypse, but they do not believe him, and shun him, so he takes his revenge by killing them all, thus bringing about the Apocalypse he saw. It would appear that he died and came back to life, for "vengeance from the grave kills the people he once saved" is a line from the song. 