At the end of his series, Barry Allen was reunited with his long-thought-to-be-dead wife Iris in the 30th century via the advanced technology. There, they lived happily ever after... for a while. Until the Crisis started the events that led to the Flash's seeming demise. But how long did he stay in the future? One month? Two? Six? A year? Longer? Later it was established that, instead of merely being the ancestor of Don and Dawn Allen, The Tornado Twins from Adventure #373, he was their father!
Which is rather intriguing since it places Barry into the generation before the Legion. So what if there was some intergalactic threat that arose? What would Barry do if it was too much for him to do? I think that the Flash would do what worked for him before. He would help put together a team!
Now, twelve of the Silver Age Legion members, plus the Subs, came from worlds where everyone had the same power to some degree. I won't list them. Ok, I will: Braal, Titan, Cargg, Bgztl, Durla, Imsk, Colu, Bismoll, Trom, Naltor, Tharr and Zwen. But I will not be so obvious to suppose a Magnetic Man, Mind-Reader, Triple Threat, etc. Though I do wonder if those planets had heroes of their own with different powers? I will make one exception later.
There are three Legionnaires with heroic predecessors. If there is a Brainiac 5, logic dictates that there was a Brainiac 4. Now Brainy was one of the Legion orphans but his ancestry is known to us all. A super-smart Coluan would be welcomed if the Flash can accept the help of a Brainiac!
Shadow Lass's father, Shadow Lord/Shadow Man, was her people's champion. In fact her entire bloodline were Talok VIII's defenders.
Karate Kid's mentor, the Sensei, was a super-hero, capable of shattering inertron! In fact he had his own arch-nemesis, the Black Dragon who was Karate Kid's father! His name was given as White Crane, IIRC.
If Barry went to his JLA roots, it would be hard. The Legion canon tells us little, if anything, about the fates of Atlantis or Paradise Island. His fellow members may have had descendents but no super-heroes. Well, maybe...
In Superboy and the Legion #217, we meet Laurel Kent, a Super-prodigy who inherited Superman's invulnerability, and may I add, a Mike Grell babe. I doubt that she had all his invulnerabity, probably more like 75%, which ain't chopped liver either. But what about her father, also a Super-prodigy? How much of Superman's powers did he have? Even if it was Action Comics #1 levels, he would be useful. And yes, I do know know Laurel's Post-Crisis status, but I'm ignoring it! It's my topic!
The Flash could always get a top-notch Wingman from Thanagar, someone who also was awarded the Honor-Wings like Katar Hol. (I still believe in the Silver Age Hawkman!) Hopefully he'll have more offensive weapons than a mace!
In Superman #295, we learn that the Green Lantern of Space Sector 2814 in the 30th century was an alien named Xenofobe who also battled the Time Trapper. And Green Lanterns were not yet banned from Earth during this era. And the Flash works well with a Green Lantern.
Celebrand of the Wanderers fits in nicely here but I never understood what exactly he does!
I would like to add Marla, the Legion's senior advisor from Superboy #98 to the team as he looked like a super-hero, wearing a costume similar to Ultra Boy's but with a different insignia. But sadly, he was later downgraded to R.J. Brande's right hand man.
Also possibilities are the "deceased" heroes from Adventure # 341:
Mog Yagor of Vasmoor, who looked like an Adam Strange type.
Leeta 87, "defeated innumerable super-villains", bad with fruit!
Nimbok of Vaalor, a mutant magician(?), his race's savior and a bad judge of character.
And the most compelling of the bunch: Hate-Face who had "the face of a devil, the soul of an angel" who "rescued millions" so I'm betting that he was more than a two-fisted brawler. Did he die in battle or "of a broken heart"?
They are all such mysteries that they can fill any role!
Can anyone else add to these Imaginary Justice Leaguers?