Here is how Celestia orders the assembling of Team Moon Dancer in Equestria Civil War.
(we see Figge and Scotch come in)
Princess Celestia: What is it, you two?
Figge: Report, we have just learned that Nighlock is gathering friends of his together and meeting with them. Twilight has been doing the same.
Scotch: We suspect they might be plotting to rebel and fight this new law.
Moon Dancer: But that's pointless!
Princess Celestia: Moon Dancer.
Moon Dancer: Yeah.
Princess Celestia: I am tasking you with bringing them all in.
???: Then perhaps I could be of assistance.
(they turn and see Amanda Waller)
Princess Celestia: May we help you?
Amanda Waller: You can't beat Nighlock or his allies. They're superhumans. Which is why you need Superhumans to deal with them.
Moon Dancer: Gather your Superhumans, and meet us back here.
Amanda Waller: I will.(leaves)
(cut to Joe's Donuts in Canterlot)
Donut Joe: Would you like an eclair, Princess? They're fresh and have just arrived.
Princess Luna: Thanks, but I'll stick with the chocolate donuts.
Donut Joe: No problem, Luna. have good day.
Princess Luna: You too, friend Joe.(leaves the Donut Shop)
Moon Dancer: Why am I not surprised I found you here?
Figge: Because she and Celestia love Joe's Donuts.
Scotch: Then again, who wouldn't?
Princess Luna: Whatever it is, we didn't do it.
Moon Dancer: You're not in trouble. We have reason to believe that Nighlock and Twilight are rebelling against the new law, and are gathering followers. And I want you on my team.
Princess Luna: If she has truly betrayed Equestria (in Royal Canterlot Voice) THEN SHE MUST BE DETAINED AND PUNISHED!!!
Moon Dancer: So you in?
Princess Luna: Yes. Where do we go?
Moon Dancer: You get Rarity and Pinkie. Scotch, Figge, you two find Thorax. I'll get Sunset, Adagio, Aria, and Sonata.
Princess Luna:(flies off)
Scotch and Figge:(fly off as well)
Moon Dancer:(enters the portal to CHS)
(at Carrosel Botique)
(we see Rarity working on a new dress)
James: Rarity, I know you're busy right now, but can we talk?
Rarity: In a moment, James.
Sweetie Belle: But it's important.
Princess Luna:(enters the room) James, Sweetie Belle, could you give me and Rarity a few minutes, then you can talk to her.
Sweetie Belle: Oh, alright.
Rarity:(drops her work) Princess Luna! What a surprise. What can I do for you?
Princess Luna: Are you aware of what Twilight Sparkle has been doing lately?
Rarity: I only know that she hasn't come out of the castle. This law hit her the hardest, as this was something she was never taught. It goes against everything she ever learned. Why?
Princess Luna:(sadly) She may be working with Agent Tavary to take down this new law.
Rarity: But that's impossible! She would never turn against Celestia or Equestria for that matter! And even if she is, it's impossible to fight it!
Princess Luna: Well has anyone been monitoring her actions lately? Has anyone kept an eye on her?
Rarity: Spike hasn't because he doesn't want any part in this.
Princess Luna: Please, help us bring them in. We have to try to keep them from tearing Equestria apart.
(after thinking for a moment, Rarity agreed)
Princess Luna: James, We want you and the other engines on this team as well.
(James and Sweetie enter)
James: That's what we've been trying to say here! Me, the Crusaders, and the other engines want no part in this! Neither do the Autobots and Dinobots!
Princess Luna: Seriously?
James: This law is for Equestria, not Equesodor. This isn't our fight. It's yours.
Rarity: So you're all going to abandon us at this time?!
James: Maybe we are. But we're not getting involved. I'm sorry Rarity, but this isn't our fight to fight.
Princess Luna:(to Rarity) Wait for us at Canterlot Castle.
Rarity: Will do.(heads to the train station)
Princess Luna:(walks to Sugarcube Corner)
(inside Sugarcube Corner)
Pinkie Pie: Mr. and Mrs. Cake, I've got the strudels! They've just arrived!
Mr. Cake: Set them in the kitchen, Pinkie.
Princess Luna:(enters as Pinkie sets them down)
Mrs. Cake: Princess Luna. We didn't know you were coming.
Princess Luna: We only wish to speak with Pinkie.
Pinkie Pie:(enters) Why?
Princess Luna: Twilight may be helping Nighlock fight the new law. This could mean trouble.
Pinkie Pie: So you want me to join Moon Dancer's team, I'm in.
Princess Luna: That was easier than we thought.
Pinkie Pie: I'll be at the castle, bye.(leaves)
Princess Luna: We better head back as well.(flies off)
(cut to Thorax flying around)
(Scotch and Figge join him)
Thorax: Oh hey, guys, what's up?
Scotch: We only wanna talk.
Thorax: We're doing it while flying then.
Figge:(to himself) Yes.
(they fly around until Scotch speaks first)
Scotch: Obviously, you're wondering why we're here.
Thorax: Yeah I am.
Figge: Twilight and Nighlock are trying to fight the new law. They're rebelling.
Scotch: It's true. They've been going to their most trusted friends. They're gearing up, so we have to gear up as well.
Thorax: Where too, then?
Figge and Scotch: Canterlot Castle.
(they fly to the castle)
(cut to CHS)
(we see MD come out of the portal)
Moon Dancer:(walks into the school)
(cut to Sunset fixing the Dazzlings cellphones)
Sunset Shimmer: And they're good to go.
Adagio Dazzle: Thank Sunset.
Sunset Shimmer: Remember, if you need anything else, let me know.
(MD walks by, and sees them)
Moon Dancer: Girls.
Sunset Shimmer: Oh, hey, Moon Dancer. What's going on?
Moon Dancer: Your friends, Twilight and Nighlock, have decided to rebel against the new law in Equestria.
Sonata Dusk: What law?
Moon Dancer:(places down the Accords)
Aria Blaze:(puts on her reading glasses and reads the law) So you want our help to bring em in?
Moon Dancer: Yes.
Sunset Shimmer: Twilight and any other rebel Equestrian, we can handle. But Nighlock and his allies are Superhumans. What chance do we stand against them?
Moon Dancer: A big one with a little help from Director Waller.
(After thinking for a moment, they agreed to sign)
(cut to Belle Reve Prison)
(guards come into Harley's cell)
Guad: Let's go. You Squad people have a new mission.
Harley Quinn: Where are we going?
(We see the guards going to get Deadshot)
Deadshot: Can I help you?
Guard: New mission for the Squad.
(cut to Croc's cell)
Guard: Where you hiding? The Squad's got a new mission.
Killer Croc:(yawns) Is it time to get up already? Five more minutes.(goes back to sleep)
(the guards look at each other, and then carry him to the plane)
(cut to the Military Base)
(guards bring the Squad, who are still wearing their prison uniforms, to Rick and Katana)
Crossbones: What's goin' on, Rick?
Rick Flag: We're going to Equestria to help them detain Twilight Sparkle and Nighlock for rebelling.
Captain Boomerang: Do we get cake if we succeed?
Rick Flag: They might, but you won't.
Captain Boomerang: Darn it.
Rick Flag:(pulls out an IPad) Behold, the Voice of God.
Taskmaster: Why do you call her that?
(Waller's face appears on screen)
Taskmaster: What's the deal, Waller?
Amanda Waller: We need help, because without Superhuman aid, Moon Dancer's team is screwed. There will be other Superhumans who join us.
(cut to Central Command)
Darkstar: Red Guardian, where are the tools to fix the ship?
Red Guardian: In the cell blocks.
Amanda Waller:(walks in) Hello, Winter Guard.
Red Guardian: What are you doing here, Waller?
Amanda Waller: Are the others here? I want to talk.
Crimson Dynamo:(walks in with Ursa Major) We're right here.
Darkstar: And what about Radioactive Man?
Radioactive Man:(flies in) Sorry I'm late comrades.
Ursa Major: What do you want?
Amanda Waller: This is your chance to defeat the Avengers. They're joining Twilight and Nighlock in taking out the new law.
(cut to the Baxter Building)
Human Torch: I don't know, Reed. We'll be up against our own friends.
Mister Fantastic: We have to help them. Nighlock has recruited three teams of Superhumans. We need to do the same.
(screen goes black)
(a transmission begins as we see Canterlot's symbol)
(we see an image of MD flanked by Reed and Morro)
Moon Dancer:(on transmission) I don't need to tell you that you've made the right choice. You're here, and that means you understand the reality of our situation.
(we see an image of Twilight, Piotr, and Amy)
Moon Dancer:(on transmission) You know what we're up against. We simply can't restore the public's faith in reformed villains while the Princess of Friendship and her recruits are still playing by the old rules.
(we see an image of both sides facing each other then Canterlot Royal Guards facing off against the real threats)
Mister Fantastic:(on transmission) Canterlot is going to expanded authority to keep real villains in check. That leaves us with responsibility for dealing with the rogue heroes.
(we see that the Canterlot Warriors only currently consist of Celestia, Waller, Luna, Rarity, Pinkie, Adagio, Aria, Sonata, Sunset, Red Guardian, Darkstar, Ursa Major, Crimson Dynamo, Radioactive Man, Rick, Tatsu, Floyd, Harley, Digger, Waylon, El Diablo, Rumlow, Taskmaster, Susan, Ben, and Johnny)
Moon Dancer:(on transmission) We'll be ready for them.