Who's Baron Blitzkrieg?

Who's This? A garish Nazi.

The facts: Though obviously a WWII villain, Baron Blitzkrieg was not spawned in the Golden Age, but rather created in 1977 by Gerry Conway as a foe for the Earth-2 Wonder Woman (see below). Obviously from there he would go on to appear in Roy Thomas' All-Star Squadron, most notably killing the Red Bee on a trip to Earth-X. In the 90s, he was revealed to instrumental in the creation of the hero Damage, and became a recurring villain in that series.
How you could have heard of him: Ok so maybe you saw Superboy-Prime vaporize his head in Infinite Crisis. Or caught sight of him getting skewered by Frankenstein in Flashpoint. Or show up as a zombie in Blackest Night. Or in Kevin Smith's Batman: The Widening Gyre. It's up to you to decide which is the worst fate. CW fans may or may not realize he is the same character as Baron Reiter on Arrow.
Example story: World's Finest Comics #246 (Aug-Sep 1977) by Gerry Conway, Jose Delbo and Vince Colletta

Let's go right to the source - his introductory story, told in two parts in the pages of World's Finest when it was a 100-page giant.  Our story starts with the murder of a U.S. Army general serving in the European theater.

It's a good thing London is so foggy, because it's almost inexcusable to have the Baron dressed LIKE THAT skulking around army headquarters, getting the drop on sentries, reaching his target, and making good his escape. Just sayin'. Well who else is in London? Major Trevor and Yeoman Diana Prince, of course! They're on the case! Diana is quick to note the wet carpet (look at the Baron's feet, above) and notes it is sea water. As Wonder Woman, she takes her invisible propeller plane to the English Channel (hey, how quickly did Blitzkrieg go from the ocean to London that he still had wet feet?!) and finds a suspicious dinghy and gets the lassoed truth out of the Third Reich's paid agent, a Cockney fisherman (Earth-2's UK must be as big as my apartment) who got the Baron ashore. I bet the villain spent the whole boat ride ranting about his origin story, because the Fifth Columnist knows the whole thing! How the Baron was a Prussian nobleman and a favorite of Hitler's. How he was rewarded and named commandant of a death camp. How a Jewish detainee tried to make him the Reich's answer to Two-Face...

How the surgeons saved his eyesight, but not his face, ripped to shreds by that bottle. How Hitler ordered he be used for Übermensch and fashion nightmare experiments, and renamed Blitzkrieg, the Human Thunderbolt!

Note how his powers only work for short spurts of time before he needs a rest. That's probably going to become important later. And now the Baron is going to try and assassinate the leader of the armed forces in the Middle East. But not if Wonder Woman has anything to say about it.

Ouch! Sir Claude may never walk again.  Blitzkrieg next figures out the Diana's one weakness. No, not bondage. Filing!

With that piece of concrete to the face, she dislodges his mask and he runs crying "DON'T LOOK AT MEEEEEE!!!" Okay, Phantom of the Operation Table. Wonder Woman takes the officer out of the burning building, but the Baron's escaped. Indeed, he throws a grenade at Steve Trevor (when he has a kind of heat vision?!) later necessitating another intervention by the Battling Amazon, but by the time she reaches him, he's gone after... WINSTON CHURCHILL?!

Well, no one can say he doesn't go for priority targets. But that's a tale for another day, perhaps for another blogger. But it will take Diana into the dark heart of war-torn Europe, team her up with Mademoiselle Marie, and mean the end (not the end) for Baron Blitzkrieg.

Still can't get over the costume.

Who's Next? A searcher of evil... for a fee.