So, I'm designing my own DC universe in my head and I don't know what to do with the JSA characters.
I like the legacy of the New Earth continuity. Superheroes have been in the public eye since WWII. Heroes that inspired the heroes that will go on to form the JLA. There are obvious examples like Barry Allen being inspired directly by Jay Garrick and the mantle of Black Canary being passed from Dinah Drake Lance to her daughter Dinah Lance. This sets up the tradition of the legacy hero, which will become important as the generations progress. Also, and this is surprisingly not commented on much, Alan Scott (The Green Lantern) was from Gotham. Before the batfamily protected that hellscape, Alan Scott defended it against gangsters and mystical threats. How much inspiration did he have on the dark knight?
I also like the bronze age Earth-2 stories. The world where Batman, Superman, Wonder Woman, and Robin were members of the JSA in the 40s and now the second generation of heroes (Huntress, Power Girl, and Robin... again) are replacing the heroes that are somewhat retiring. On Earth-2, the mantles of the original JSA members hold too much weight for someone else to take it up, so the children of the heroes create their own. For example, Dick considers taking up the bat mantle after Bruce's passing but is convinced not to by Huntress, staying as Robin (sometimes being shown in a hybrid Batman/Robin suit).
Also, this would make the multiverse easier to establish. If Jay Garrick is already a part of the main universe, then why would you write an adaptation of The Flash of Two Worlds where Barry meets the Earth-2 version of Jay? I like the idea of using that story to introduce the multiverse because of its relatively small scale (Barry goes too fast and ends up crossing the multiversal barrier, so now a retired Jay has to help him back to his own world while stopping a scheme by Garrick's rogues), but would it confuse the audience as to why it is needed? Should I just do what they did in the comics where I start with them being separate but after Crisis they get combined?
Also, on a lesser note, can I make it a fictional war instead of WW2? I want it to take place in the modern day without the "magic spell making them age slower" reasoning. I don't think the characters are tied to any of the actual events of WW2 so it might be fine (like the heroes were not actually a part of any major battles or anything, they were just a part of WW2 propaganda pieces). Just, if Warner Bros can make a Wonder Woman set during WW1 instead of its sequel, this should be fine, right?
