The Legion of Super-Heroes
The Legion of Super-Heroes provides a door into the future. The film could put Supergirl there, instead of the past. There have been adaptations where she joins them in the future. The movies can switch it around and have her go from the future into the past.
Using the Legion also opens up the general audience to an underrated group of Heroes. Not to mention, the idea of future heroes going back to the past and watching what they say to the present is fascinating.
If the filmmakers want a relationship then Supergirl and Brainiac-5 have a past.
Also, using Supergirl in the future explains why she’s yet to be seen in the present day. Perhaps her pod ends up through a wormhole and lands in the future instead of the past.
The first movie can easily take place in the future and have a Back to the Future vibe. In the future, something horrible happens that makes Supergirl and Brainiac-5 need to go the past.
The story provides a dynamic where Supergirl sees her cousin again and decides to stay in the past, giving up Brainiac-5 and the rest of the Legion.
Using Supergirl in the Legion’s first movie will bring in the general audience. Thanks to The CW’s Supergirl and DC Super Hero Girls the character’s popularity is rising.
Forgetting Supergirl, the Legion also has Dreamer, Saturn Girl, Mon-El and a collection of very interesting heroes. They can act as heralds for dangers to come while stopping their own threats in the future.
If DC wants their own Guardians of the Galaxy-type using the Legion of Super-Heroes is their way forward.
