Recently, BJ Blazkowicz, the hero of the original Nazi shoot-em-up, Wolfenstein 3D, was confirmed to be Jewish through his mother. Terrific, in the grand scheme of things! BJ (terrible name, but whatever) is only one of the most groundbreaking characters in video game history.
Which brings us to Commander Keen. You remember Commander Keen, right? The little kid in a yellow helmet and purple t-shirt? Shooting aliens? Jebus, was 1990 really so long ago?...
In any case, Keen comes with a backstory. His real name is Billy Blaze, with Blaze being shortened from Blazkowicz. In fact, Keen's full name is William Joseph Blazkowicz II. He is BJ's grandson.
(We pause to ponder here. BJ was hunting Nazis in the 1940s, and Keen is hunting aliens in what year? Let's see, that's two generations... You know what, never mind. Let's just say that they live in a parallel universe where Nazis and aliens overlap.)
But wait, fans of 1990s video games, there is more! Keen had a son... William Joseph Blazkowicz III, better known as Doomguy, the main character of that other shoot-em-up classic, Doom.
You know, it's best not to think too much about this.