OK,
Yes, Alex and Superboy-Prime are villains and have been going back and forth from their "prison" all along.
Thankfully, Earth-2 Superman and Lois have no clue about them, and are therefore NOT VILLAINS, thank Rao. Though, I wonder how Mr. Old School will react when he finds out.
Speaking of old School Speed Force is no more! and Julian rejoices
The Sliver Age Flash returns at long last, remember he was never really dead, just trapped.
oh and ....
the Multi-verse returns or at least Earth-2.
Tomorrow we should have a lot more details.