Jecht: I get to fight with the best fighter in the world!
Cloud: Not you again.
(Leela and her Alternate Universe counterpart do the exact same kick and knock each other unconscious)
Professor Farnsworth: Now, now; perfectly symmetrical violence never solved anything.
Green Lantern: Save it. Time to kick my ass.
(one fight later)
Green Lantern: Well, that was surreal.
Wonder Woman: And a bit disturbing.
Green Arrow: Yeah, all of that yellow is really tough on the eyes.
Main Universe Batman: You expected otherwise?
Insurgency Batman: Call it a draw?
Main Universe Batman: Not our style.
Regime Superman: I saved this world!
Main Universe Superman: Now I'll save it from you.
Regime Solomon Grundy: Like looking in mirror!
Main Universe Solomon Grundy: Grundy hates mirrors!
Main Universe Solomon Grundy Grundy think you look handsome!
Regime Solomon Grundy So does Grundy!
Main Universe Joker: (Draws crowbar) Got a joke for you.
Regime Joker: (Draws crowbar) I've probably heard it.
Fake Twilights: They're changelings, remember? (evil smile)
(Gibbs walks up behind Abby)
Abby: Oh, oh that's good! Okay, so um, evil twin or a clone?
Squigly (Match Start vs Squigly): What a shameless imitation.
Cerebella (Victory vs Cerebella): This ring's not big enough for the two of me!
Peacock (Victory vs Peacock): I'm the real deal! Accept no substitutes
Squigly (Victory vs Squigly): Your flattery needs work.
Eliza (Loss vs Eliza): How fitting...
Colonel: Snake, what's going on out there?! Could it be...? Has the "Les Enfants Terribles" project really come this far?!
Snake: It's more than that! He's got my moves, my gear... It's like looking in a mirror!
Colonel: Do you think they collected data on you, and created another Snake?
Snake: He's got the same build, too. Creepy. But his Sneaking Suit is a different color. And his tactics are slightly different.
Colonel: Interesting. So even if you're evenly matched in power, your fighting styles will make a big difference. You've faced tougher odds in the past, Snake. Don't let this impostor beat you!
Palutena: It certainly appears to be the case.
Pit: You're awfully calm about this, Lady Palutena!
Palutena: Well, we've been through a similar situation in the past, don't you recall?
Pit: Yeah, but it's still freaky! It's like looking through a twisted mirror! ...That reminds me: you know how Dark Pit came from a mirror? Then why doesn't he move left when I move right, and vice versa?
Palutena: Beats me.
Pit: But you're supposed to know everything! Don't you have an all-seeing eye and all-knowing brain and all that?
Palutena: My all-seeing eye sees you getting hit.
Pit: Aww man, really?
Palutena: I'm sure the true Pit would triumph over any doppelganger. So I guess now we'll see if you're the real deal.
Cassie Cage 2: You know what's funny? Your face.
Cassie Cage 1: Dude, you've just insulted yourself...
Scorpion 2: The sight of you offends me.
Scorpion 1: Your death will be swift.