I think everyone must have considered this at some point now. Whether it will happen I don't know but it is certainly something I've wondered about whether they actually can, it may be too difficult as it may result in the wiping of season 1 of Supergirl. Other than the Flash crossing over the only link I can think of is that they've both shown a Legion ring. So for me the easiest way to do it, and might involve a big crossover event including Supergirl, Flash and Legends of Tomorrow. I don't think Arrow would need to be involved but still could.
For me some sort of incident caused by the upcoming Flashpoint results in Flash, Supergirl and one or two Legends being dragged to the 31st century. The rest of the Legends travel forward, possibly bringing Green Arrow if they want to do a big event, to save them. In their efforts to travel back they can only return to one Earth, the other would be destroyed. Or at least could never be accessed again. Obviously Earth 1 would be chosen but some loopholes might allow them to merge the Earths and that would somehow bring in the Supergirl cast into the CWverse. I mean now we have Superman they could easily do it where he is bright to the future also but he sacrifices himself to merge the worlds. And that would deal with the criticisms of why doesn't Kara just ask Clark for help as he would no longer exist and it's the sort of selfless act Superman would do.
I really hope it doesn't go that way and the writers could find a better way to do it but in my head right now this is the only plausible thing I could think of. Flash's ability to time travel and cross Earths and the Legion are the only things that link them at the moment. And I also don't think Hoechlin's stint as Superman will be a big one. Obviously Arrow is the only show we've heard of with known restrictions on characters but we can't be ignorant and claim that none of the other shows have these same restrictions. Especially when the worlds of Flash, Supergirl and LoT can't meet a much larger range of heroes than Arrow ever would have. I believe that DC are definitely being more lenient with characters now due to how popular the shows are or whether to use the shows as a way to build up support for their heavily critiqued film universe but I don't know. I don't think Superman will be around for long.
But still I'd love to hear people's thoughts and theories on it or if they think my idea is the most plausible.
For me some sort of incident caused by the upcoming Flashpoint results in Flash, Supergirl and one or two Legends being dragged to the 31st century. The rest of the Legends travel forward, possibly bringing Green Arrow if they want to do a big event, to save them. In their efforts to travel back they can only return to one Earth, the other would be destroyed. Or at least could never be accessed again. Obviously Earth 1 would be chosen but some loopholes might allow them to merge the Earths and that would somehow bring in the Supergirl cast into the CWverse. I mean now we have Superman they could easily do it where he is bright to the future also but he sacrifices himself to merge the worlds. And that would deal with the criticisms of why doesn't Kara just ask Clark for help as he would no longer exist and it's the sort of selfless act Superman would do.
I really hope it doesn't go that way and the writers could find a better way to do it but in my head right now this is the only plausible thing I could think of. Flash's ability to time travel and cross Earths and the Legion are the only things that link them at the moment. And I also don't think Hoechlin's stint as Superman will be a big one. Obviously Arrow is the only show we've heard of with known restrictions on characters but we can't be ignorant and claim that none of the other shows have these same restrictions. Especially when the worlds of Flash, Supergirl and LoT can't meet a much larger range of heroes than Arrow ever would have. I believe that DC are definitely being more lenient with characters now due to how popular the shows are or whether to use the shows as a way to build up support for their heavily critiqued film universe but I don't know. I don't think Superman will be around for long.
But still I'd love to hear people's thoughts and theories on it or if they think my idea is the most plausible.