Mittelstaedt was inspecting an electrical power plant when a stray bolt of lightning struck a faulty generator and bathed him in electricity. When he emerged from his coma weeks later, he found that he could summon lightning at will to wield as a weapon. With these powers, he called himself Blitzkreig and began a career as a costumed crime fighter. At one point, he was transported alongside various other international heroes by the alien Grandmaster in order to participate in a so-called Contest of Champions,he was unable to defeat Storm. He later assisted Captain America (Steve Rogers) during the contest then he returned at the end of the encounter. Later, he was seen among those who helped the spaceknight Rom against the alien Dire Wraiths.

At some point, Mittelstaedt joined a group of German superheroes, the Schutz-Heiliggruppe, and he was among their number when the team was sent to remand the Nazi criminal Red Skull to Germany to stand trial for war crimes, although the Skull later escaped.

Later still, Mittelstaedt was on assignment in South America where he was accosted by the villain Zeitgeist, also known as Everyman, who killed Mittelstaedt. Mittelstaedt is survived by his wife and son.