Identity Reveal(s)
Their identities would be revealed during the Crime Syndicate, with a focus on Dick's life being in danger. Damian's struggle will be different since Talia is dead and will not kill Damian. He will probably get kidnapped and get injured, but he'll be able to get through and decide to help Dick. Damian will break in with a katana, and he can either be dressed as Robin or as Damian with baby assassin skills. I think Robin would be better for this scenario, but it can go either way. Dick will be revealed to the world as Nightwing. This time, it will shock his entire family, along with the rest of the world.
The (Not) Bat-family siblings is rounded up and put in a secure location by Wally West as Flash or Kid Flash for protection. Superman or Wonder Woman also go to personally get Bruce from Wayne Industries, where he is clearly distraught over Dick being in trouble. Bruce also gets into wanting to help Dick, but feeling powerless to do so. While there they are reeling from the reveal. The only one who is not taken in, not counting Damian, is Jason, who was doing work as an informant. Before Wally can get to him, he's taken by either Deathstroke, a Crime Syndicate member, or the Court of Owls on the way to Wayne Manor; I'm leaning toward Deathstroke but a Crime Syndicate villain would probably make more sense. Stevie goes to the manor after the reveal and finds evidence of the struggle. She goes to find Jason.
Dick is locked in the death machine. Lex Luthor won't be there to kill him since I'm not sure why he would be there without Batman. Instead, Damian, preferably as Robin, finally gets to Nightwing, interrupts the transmission, and manages to get him out, and he can have some kind of healing medicine, or even a minor amount of water similar to (but not exactly like) what's used to revive people in the League. Giving this to Dick saves his life, although he's still a little banged up.
Meanwhile, Jason is also broadcast for the world to see as the brother of Nightwing, which is where Jason finds out the truth about Dick and falls apart at his brother dying and being a hero without him knowing. Stevie finds where Jason is and she sneaks in. Before this, she also gets contact from Dick that he's alright, and after expressing his relief, she informs him of what's happening to Jason, and that she's found where he is. They come up with a plan to rescue Jason and stop the bad guys. She walks into the scene, seemingly innocuous. Stevie is serving as a decoy and buying Dick some time. When they come after her, she starts fighting the henchman, and it becomes clear who she is once Stevie throws her shield to protect Jason. Someone tries to get Stevie to back down by aiming a gun at Jason. During this fight, they cut back to the scene of Nightwing, who is now gone from the death machine, and the bomb has clearly been removed.
Then the villain asks where Nightwing is, and Nightwing shows up in his banged up suit and still unmasked. He can either comes out of the shadows and grab the bad guy's arm, getting him away from Jason, or he can jump from above and punch the guy holding Jason.