The season three finale of Black Lightning, titled "The Book of War Chapter Three: Liberation," finally gave fans something that they have been waiting for since the series debuted: Tony Isabella, the writer who created the character of Black Lightning, and Trevor Von Eeden, the artist who created the character with Isabella, finally got to make their Stan Lee-style cameos. The pair appeared onscreen together, and even got name-dropped, so that Isabella and Von Eeden are canonically a part of the Arrowverse's Earth-Prime world -- albeit not as comic book creators, of course. They appeared in the final moments of the episode, so you know what that means.
That's right: spoilers ahead. Don't read past this point unless you're ready to know how "The Book of War" (and Black Lightning's third season) ends.
In the early part of the episode, and as the trailers revealed, it turns out that the ASA has decided to abandon Freeland. Whether or not the Markovians win, the ASA is leaving town. And if the Markovians DO win, they're going ot nuke the whole place to prevent the other side from getting their strategically important metas and research.
That doesn't work out quite the way they want it to. When the Markovians are stopped, Khalil (Jordan Calloway) stows away in the back of Odell's car, and shoots him in the back. It is not a life-threatening injury, and Khalil hands him off to Black Lightning to face the consequences of the ASA's actions, but it's emblematic of how things go. Most of the recognizable ASA agents from this season are killed, while others are taken into custody and prosecuted, with Black Lightning providing testimony before a tribunal and handing them the briefcase that has been at the center of so much grief since the show's first season as evidence.
The idea of giving the pair a cameo, and making them judges, makes some sense in the world of the Greg Berlanti-produced Arrowverse shows. In the early days of Arrow, a running bit was that many of the judges in criminal cases had the names of comic book creators who had worked on Green Arrow and other DC Comics properties. Of course, actually giving people cameos is a bit rarer -- although Marv Wolfman did get one during "Crisis on Infinite Earths," and it was pretty great.
Black Lightning will be back for the 2020-2021 season. In the meantime, you can stream the last few episodes of this season The CW's website or app, and you can see the first two seasons on Netflix, where season three will be in a few short weeks.