Apart from the Leaguers seen in the last episode, we can see throughout this episode Dr. Light (flying to the control center); Aztek, Booster Gold, Gypsy and Crimson Fox (sitting on the table); Blue Devil and Vixen (on the control center); Green Arrow and the Crimson Avenger (on the teleporting platform); Starman (in the Metro Tower); the Atom, Stargirl and S.T.R.I.P.E., the Question, Ice, Fire (being consecutively teleported); Commander Steel (on Shayera’s team); Shining Knight, Vigilante; Black Canary; Hawk, Dove, the Creeper; Zatanna; Doctor Mid-Nite and Thunderbolt (walking down the staircase of the Metro Tower); B'wana Beast, Hourman, Wild Cat, Vide and Elongated Man (running down the staircase).
The New God who "helped" Lex and crew was Lightray, who had a role in the season two episode "Twilight."
Hawkman returns, without any dialog.
Blue Devil has one line, but is not credited.
After getting back from The Source Wall, Lex is donning the same business suit he wore in Superman: TAS
As the JLU run down the staircase towards a brief close up on screen before vanishing from view, the last close up, which indeed smothers the screen before the credits, is the Bat symbol on Batman’s' costume, an attempt by the producers to bookend the last present day DCAU series with who first began it. A similar stunt was done on a much more episodic scale with "Epilogue", which focused entirely on Batman’s' universe.
Shayera: Send us first – give the others the chance to get their pants on.
Giganta: (to Superman) If you think you’re locking us up while the whole world is under attack, you got two fights on your hands.
Superman: Oh, come one, it’s Lex-flipping-Luthor! Why should we trust him?
Lex Luthor: Let’s be clear about this: we’re not here to help you save the world-–you’re here to help me get revenge on Darkseid. When this is over, it’s back at business as usual.
Superman: Wouldn’t have it any other way.
Lex Luthor: Is there a plan here?
Batman: Keep attacking the small fry until we attract the big thing's attention.
Lex Luthor: Hah, with all that's happening here, I bet he never notices us. (Darkseid arrives)
Batman: You're on.
Superman: I'll take some of that action.
Darkseid: I hope you appreciate, Kal-El, that everything that happens from this point is on your hand. The skies will rain fire, the oceans will boil, the streets will run red with the blood of billions. Only then, after your last pitiful hope is extinguished, will I end your life. Let’s go.
Lex Luthor: You destroyed Brainiac! I'm going to make you pay!
Darkseid: I’m more powerful than I’ve ever been and the last time we met, you barely managed to hold your own.
Superman: Funny--that’s not how I remember it.
Lex Luthor: (hands Batman a gun) Take my extra.
Batman: Not my style.
Lex Luthor: Suit yourself--I’m planning to live through this.
Darkseid: (to Batman) Impressive. No one has ever avoided my Omega Beam. I wonder if the other one is as agile. (Lex runs) Excellent strategy.
Darkseid: (to Superman) Super or otherwise, you’re merely a man, and I am a god!
Metron: I warned you that you were dabbling in forces beyond your comprehension.
Lex Luthor: You'd be surprised what I can comprehend.
Superman: (about Batman, to Darkseid) That man won't quit as long as he can still draw a breath. None of my teammates will. Me? I've got a different problem. I feel like I live in a world made of cardboard--always taking constant care not to break something, to break someone. Never allowing myself to lose control--even for a moment, or someone could die. But you can take it, can't you, big man? What we have here is a rare opportunity for me to cut loose and show you just how powerful I really am.
Darkseid: (to Superman) It’s called the Agony Matrix---direct neural stimulation of pain receptors. All of them. Imagine the worse pain you’ve ever felt in your live, times a thousand. Now imagine that pain continuing forever. Oh that’s right--you don’t have to imagine.
Metron: I warn you one final time--only a twelfth-level intellect has the slightest hope of surviving what you are about to experience.
Lex Luthor: Then I’m overqualified.
Darkseid: Still alive. You impress me, Kryptonian. More... your valor has touched my heart. Oh yes, there is still some small part of me that knows mercy. I will end your pain with something special I’ve been saving for just this occasion (takes out a kryptonite knife). I’m going to carve out your heart and put it on a pike in my throne room.
Wonder Woman: It’s past time that Luthor’s partners in crime were locked up.
Atomic Skull: Wait a minute--we help you guys save the world and we don’t even get any consideration?
Batman: You’re right--five-minute head start.
Atomic Skull: Five minutes? Are you kidding?!
Wonder Woman: Four minutes, fifty seconds.
J’onn: (on the cell phone to his wife) I should be back in time to dinner. I love you too.
The Flash: These are the end times...
Superman: (to Batman) A head start? You’re getting soft in your old age...
Batman: Don't you have a tall building to go leap?
Wonder Woman: And the adventure continues...
Darkseid putting his leg up into Superman's back in an attempt to break it bears striking resemblence to what Bane did to Batman in the comic book story arc Knightfall.
A Streetcar Named Desire
Lex Luthor: And stranded more than a power ring’s charge from home, we found ourselves dependent on the kindness of strangers.
This line echoes a famous quote from Tennessee Williams's play A Streetcar Named Desire. Its main character, Blanche DuBois, is a woman who, as she puts it, has “always depended on the kindness of strangers.”
Commander Steel throws a shield in the style of Marvel Comics superhero Captain America, with whom Commander Steel shares some resemblances.
The teaser features clips from the previous episode "Alive!".
I’m more powerful than I’ve ever been and the last time we met, you barely managed to hold your own.
Funny – that’s not how I remember it.
The closing credits feature clips of the previous episodes "Grudge Match," "Chaos at the Earth's Core," "Shadow of the Hawk," "I Am Legion," "To Another Shore," "The Great Brain Robbery," "Patriot Act," "Ancient History," "Flash and Substance," "Dead Reckoning," and "Alive!(1)."