hi
the Earth in video is Earth 73 not Earth 38 that mean Earth 38
meybe will save

Do we know if we get any non-Arrowverse cameos in part 1 (Supergirl)?

I think the Kevin Conroy scenes with Melissa is in part 2 (Batwoman).

I am a little shocked and disappointed that Lex's big return will not be in the Supergirl episode where he was originated. It doesn't sound like Brandon Routh's Superman will be in part 1 either.

Quoting SuprgrlFn:

I kind of hate this whole storyline even though I do know it is inspired by the canon event of the same name. I never like “resets”. Does this mean that Clark and Lois of Earth-38 won’t have their child? Will Argo City still exist out in space? I mean even if all the people of Earth 38 are “transported” to Earth 1, what about all the other Earths?

I just feel like it does a disservice to the character arcs we’ve already seen because we will have no idea if/how they happened and what “made” the characters in this new universe. Of course it’s great for the writers because they can now ignore the seldom-referenced show “Bible”.

That's certainly a risk.

I make no predictions on how it'll turn out. But I take comfort that COIE, like Avengers Endgame, would make for a natural "jumping off" point, should one be so inclined.

From how I understand it, the aftermath of the Crisis based on the comics (if the PTB will be faithful to the story) - the multiverse will merge into a universe and nobody except a few will even remember there was a crisis. That's why "Supergirl" and "The Flash" are expected to conclude their Leviathan and Bloodwork stories respectively on episode 8 just before the crisis starts. I will not be surprised if the survivors of Earth 38 will just act as if the The Flash and Green Arrow always existed, and vice-versa for the people of Earth 1 when it comes to Superman and Supergirl (as they go on about their lives).

I think not even a crisis of this magnitude will shake off Lena's fury on Kara's dishonesty to her, so she'll continue on plotting against Supergirl.

Which comes to my suspicion that Oliver will probably not die, but will be one of the few who will remember there was a crisis, and therefore he'll be sent to the "Paradise" dimension as like the Superman in the Crisis comics. There was a spoiler about it in an episode of "Arrow" near the end of Season 7.

Quoting Fedguy:

So they did say the universes are merging, but I do wonder how the independent story of Supergirl the show will continue if Earth 38 is destroyed, as the same institutions and other bits of the setting aren't on Earth 1.

If the two blend, then some things are gonna disappear or change. Gonna be funky

Earth-73 is likely the home of the Super Friends. The building that the heroes are in is likely the ruins of the Hall of Justice.

Remember Superman's cape being flagged like Doomsday? It could belong to the Superman from the Superfriends than either KC Superman or Smallville Clark.

I think the heroes that Harbinger gathered are going to travel to other Earths besides Earth-73 in an attempt to save them in the Supergirl part. In the Batwoman part, they look to be traveling to the Kingdom Come Earth, where Clark, Lois, & Iris meet KC Superman while Kate and Kara meet KC Bruce Wayne.

Supergirl could refer the Planet to the Daily Planet and saving the people there.