The Black Lightning episode tied in between Crisis 2 and 3. It showed the anti-matter wave approaching their Earth and everything happening before Black Lightning was transported to Earth 1 in Crisis episode 3.
Mainly, it showed his daughter Jen and what the Earth 1 and 2 versions were of their whole family.
It was a decent episode. I've never seen the show but it had more visual style than the other Arrowverse shows. I don't think the Earth-1 and Earth-2 shown on this episode corresponded to those numbers in the Arrowverse. Which Earth is BL on in the Arrowverse? He's no just on their Earth-1?
It was a good example of a comic book crossover issue, where they don't advance the plot of the crossover but they show its effects on the characters. In this case the red skies cause Jen to phase into two parallel realities so she can see what life would be like if she made different choices, I guess.
Are the Markovians evil on this show? Have Geo-Force and Terra shown up?