What song by Ozzy Osbourne does he refer to himself as both the iron man anti christ?

The song you're thinking of is "Iron Man" by Black Sabbath, not Ozzy Osbourne. While Ozzy was the lead singer of Black Sabbath when the song was released, he doesn't refer to himself as both the Iron Man and the Antichrist.

The lyrics are actually about a man who travels into the future and sees the destruction of humanity. He tries to warn people but is ignored, so he returns to the past as a "Iron Man" and decides to destroy the world himself.

The "Antichrist" reference is a misinterpretation of the lyrics. It's likely people associate the song with the Antichrist theme because of the song's dark and apocalyptic imagery.