A new Black Lightning
Jefferson started this series in a bathtub beaten and bloody as he told Lynn that he was done being Black Lightning. It would make sense for the show to end this way as well. Maybe not with Jefferson bloody, but with him retiring.
Jefferson wants to marry Lynn again – something he revealed in episode 11. One thing that may sweeten the pot is giving up being Black Lightning forever. However, his retirement would mean that Freeland would need a new hero. And Jennifer (or J.J.) will step up to the challenge.
It definitely seems like this is the route they are taking as the show heads towards its series finale. Jennifer’s popularity on social media may lead to her becoming a world-renowned hero, especially after exposing Chief Ana Lopez for calling metahumans “scum”. After their inevitable fight with a now super-powered Chief Lopez, Lightning may be seen as the person who’s truly watching over Freeland – especially since there haven’t been a lot of Black Lightning sightings this year.
With a new hero, Jefferson would get to step back and be happy with his job and wife. Meanwhile, Jennifer can become the hero she’s always wanted to be. Not only that, she can carry the Black Lightning legacy. And with that, it would be nice if we got Jennifer, the new Black Lightning, in another Arrowverse project.