Here's how the final showdown goes in Thomas and Twilight Sparkle's Adventures of Star Trek: Beyond.
Diesel 10: Bah, who needs Krall? We can still defeat you guys!
Tirek: Yes. But first, I wanna suck some magic out of you.
[then the royals fly into the scene]
Princess Celestia: Not on our watches!
Tirek: WHAT!? How is this possible?! I stick you in carbonite!
Barret Barricade: That maybe so, Tirek! But Bardock, Kida, and Dawn have found all the pieces of the puzzle, and they melted us out!
Princess Celestia: And you're now gonna pay for what you've done! [ignites her lightsaber]
Princess Luna: You will pay big time!
Cadance: And your face will be planted to the ground!
[The 2 and Barret ignite their lightsabers]
Belle: Mind if I join in?
Jasmine: And me?
Princess Celestia: Don't mind if we do.
Anna: Count me and Elsa!
Judy Hopps: Oh, I'm gonna make this guy pay too!
Barret Barricade: Then you're all welcome.
[They all ignite their lightsabers]
["Great Air Battle" begins playing]
Tirek: Tss. Big deal. [ignites Mace Windu's lightsaber] This time I will make you all go to the ground!
[They all clash their sabers]
Ernie: I think it's time to settle with you, Peter!
Peter: Bring it on!
[The 2 began their big fight]
Adagio Dazzle: So if this is a big battle, then? Then let's battle. [deploys her lightsaber]
Brian: That's a risk your gonna have to take! [deploys his lightsaber]
[The 2 clash their lightsabers]
[Meanwhile with the duel of Tirek, the royals, and Judy they are spinning their lightsabers around and clashing with them]
Tirek: Your powers are weak, old woman!
Princess Celestia: You can't win, Tirek. If you strike me down we shall become more powerful than you can possibly imagine.
Tirek: You should have not come back.
Princess Celestia: Well, you should know that saber does not belong to you!
Tirek: I'm afraid it does!
Princess Luna: (in Royal Canterlot voice) NO IT DOESN'T!!! THAT'S MACE WINDU'S LIGHTSABER!!!
[They resume their duel]
[Meanwhile with Peter and Ernie, they are dueling in a cargo bay. Ernie bangs Peter's head on a wheel, but Peter unleashes steam on Ernie's eyes making him yell in pain. Then when he goes to hit Peter with a wrench it gets tangled in chains, Peter punches him and pulls a lever and makes Ernie go up and Peter does the same too. Ernie spins around chains, and get around Peter's left arm and Peter pulls him and punches in the face. Ernie goes up a crane arm and kicks Peter's face several times, but Peter punches him in the sweet spot and makes Ernie yell. Peter wraps chains around his neck and prepares to choke him, but Ernie uses fire on his hand to burn Peter's face and fist punches him till Peter is exhausted from fighting and grabs a hook and prepares to kill him.]
Ernie: Say your prayers, Griffin!
[Then the hook's shot off his hand]
Kitty Katswell: Not this time, Ernie!
Ernie: [turns around and looks] What? Impossible, your still corrupted!
Kitty Katswell: Well, you thought wrong!
Ernie: [ignites one of his lightsabers] You traitor!
[He pounces ready to strike Kitty, but she activates her lightsaber and blocks it, and they come to a blade lock]
Kitty Katswell: I'm no traitor, you corrupted me! And, I have someone I'd like you to meet. Meet my Padawan, Hanah Streaker!
[Then suddenly he's stabbed through the chest and he falls down as his lightsaber extinguishes. And the killer was Hanah!]
Hanah Streaker: No one corrupts my master! NO ONE!!
[Meanwhile with Brian and Adagio's duel, they are dueling near a platform and Adagio force pushes Brian! But he grabs on]
Adagio Dazzle: Say goodbye, Snoopy. [lifts up her saber and prepares to cut off his hands holding on the platform]
Sylveon: NOOOO!!!! [she uses Giga Impact for a run starter and cuts off her arms]
Adagio Dazzle: AAAAAAAAHHHHHHHHH!!!!!!
[Then Brian force grabs her Luger and shoots her pendant and explodes and she is killed in the blast and he gets back up]
Brian: So uncivilized. [throws Adagio's Luger to the ground]
[Then Aria and Sonata get behind them, and prepare to fire their lugers. But there was a gun shot]
[They look behind each other and the 2 sirens fall down dead, and the shooter was Nick]
Nick Wilde: Did I scare you?
Brian: What do you think?
[Then it cuts back to the royals, Judy, and Tirek's duel. They are getting the upper hand and makes Tirek back against the wall, and Judy leaps up and in one swift swing she cuts off his hand the one that he's holding Windu's lightsaber]
Tirek: AAAHHH!!! [grabs his arm as he moans in pain]
[the saber goes flying into the air as Judy catches the lightsaber hilt and straps it on her belt]
Judy Hopps: Surrender, Tirek. You're outnumbered.
Tirek: NO! [he fires his magic and they all fly back against the wall. And he walks up to Celestia and grabs her by the throat] It's time to take back what's mine, all those years ago. [he opens his mouth and Celestia covers her eyes fearing the worst]
Belle: NOOOOOO!!!! [she jumps in the air and deploys her lightsaber and cuts off his horns]
[Belle soon catches Celestia and lands on the ground]
Belle: Are you okay?
Princess Celestia: Don't worry about me, I'm fine.
[Then Tirek starts groaning and screaming. And there he is growing smaller, and smaller]
Tirek: [as Wade Wilson] What have you done to me?!
Princess Luna: She cut off your horns, you can no longer steal magic.
Tirek: Look, all I want is just to survive. You must see why I must have mercy.
Barret Barricade: No, Tirek. [he his I-37 pump blaster] Villains deserve no mercy.
Tirek: NO, WAIT!!!
[But Barret shoots him in the chest and later in the head. And Tirek is dead]
Elsa: You left us no choice, Tirek.
Diesel 10: Oh, boy! I'm out of here!
Percy: Oh, no you don't, Diesel 10! [he bumps him and Diesel 10 grabs on a rail]
Diesel 10: Puffball! Teapot! [the rail then breaks] TIN CANNEL!!!!! [he lands in a barge filled with sludge] Oh, well. Nice time a year for a cruise. [chuckles nervously]
Duck: Serves you right for almost destroying the Magic Railroad, Lady, capturing Latios, sinking Samiya, stealing Giratina's powers, finding the time ripple, and kidnapping those children for making a black hole!
Pepper Clark: And don't ever come back!
Suri Polomare: Oh, it's not over yet! I'm still here. Now Rarity, how about you and I duel?
Rarity: Very well.
Sweetie Belle: No, Suri wait! [gets in front of Rarity] You don't have to do this!
Suri Polomare: What are you talking about?
Sweetie Belle: Let go of the Dark Side. Just because you lost, doesn't mean you can join the Dark Side to take revenge. Let it go, and come with us.
Suri Polomare: [thinks for a minute] Never! [she draws out her S&W Model 22 Revolver and shoots her!]
Apple Bloom and Scootaloo: SWEETIE BELLE!!!!
[Sweetie Belle falls down dead]
Suri Polomare: As long as you don't miss it.
Rarity: HAAAAAAAAAAAA!!!!!!! [deploys her lightsaber and Suri does her's quickly]
[The 2 clash like crazy, and Rarity was clashing the most and Suri was trying her best to duels off. Then suddenly, Suri force pushes Rarity down a hole but she grabs on a object and holds on]
Twilight and Applejack: RARITY!!
[Then Suri kicks Rarity's lightsaber down the hole then turns to our heroes]
Suri Polomare: Now it's your turn.
Zoe Trent: Bring it on! [deploys her lightsaber]
[But then Rarity uses the Force to move Sweetie Belle's lightsaber and jumps in the air and lands in front of Suri and cuts her in half. And she falls down the hole and reveals her split body. And Rarity deploys the lightsaber away and goes to Sweetie Belle]
Rarity: Sweetie Belle! [she picks her up, and begins wielding up tears] I love you! [hugs her and cries as everyone watches in sadness and grief]
[Just then there was a coughing noise and Rarity looks down to Sweetie Belle, and she barely opens her eyes and opens them wide]
Sweetie Belle: Rarity. That was crazy.
Rarity: Sweetie Belle! [she hugs her so tightly, that it makes Sweetie Belle's face green]
Penny Ling: Uh, Rarity. I think you're suffocating her.
Rarity: Oh! [releases Sweetie Belle] Sorry.
Sweetie Belle: It's okay. Your just overjoyed that I'm not dead.
Princess Celestia: Ah! [she falls to the ground]
Twilight: Princess Celestia!
Thomas: What's wrong?
Princess Celestia: Barret! The foal's coming!
Skeeter Valentine: Wait. Foal?
Barret Barricade: [picks her up with his hoofs] We'll explain later, we have to hurry! [he hops into Thomas' cab]
[And soon our heroes make a break for it to the hospital. But unknown to our heroes, Ernie opens his eyes and shows that he's still alive!]