Here's how the Princesses fight Ernie in Equinelantis: The Lost Equestrian Kingdom.
Princess Luna: This is it, Tia! Any last words?
Princess Celestia: Yes, I really wish we had a better idea than this!
[They crash in the blimp and hop off their ship as it continues]
Ernie: We're losing attitude! Lighten the load!
Stormtrooper: Yes sir!
[they start throwing off barrels]
Stormtrooper: That's it sir! Unless someone wants to hop off.
Ernie: Good, it's you! [pushes him off]
Ernie: Nothin' personal!
Princess Luna: [ignites her lightsaber]
Ernie: Well, I have to hand it you are big pains in my egg.
Princess Celestia: [ignites her lightsaber] Return our father!
Ernie: I don't think so, becuase your father is mine. [ignites his lightsabers] YAAAAAAAHHHHH!!!
[The 3 clash their lightsabers]
Ernie: [snarls] [clashs his right hand saber]
Princess Luna: [bucks him down to the crates]
Ernie: Hey, congratulations! You just won the die card!
[The 2 alicorns come down]
Brian: Nothing personal, Ernie! [fires bazooka]
[the round flies forward and then it blows up the airship's main controls]
Ernie: The diamond shall be MINE!!!!
Princess Celestia: Look out!
Princess Luna: [ducks as he swings his sabers]
[they land outside the cockpit]
Princess Celestia: [avoids the next swing]
Ernie: Tired?! [swings again as his sabner shatters one of the windows] Because I'm just getting it warmed up!
[Force chokes Celestia and brings her up]
Princess Luna: [picks up a shard of glass]
Ernie: So long, Sun Princess. [prepares to stab her]
Princess Luna: [stabs his left leg with the glass shard]
Princess Luna: Well, I have only just begun.
Princess Luna: [swings her left leg and gets him in his stabbed leg]
Ernie: Ah! [evil chuckles] That won't stop me, once I get out a here. The world belongs to me!
Princess Celestia: No, it won't! You may have kidnapped the diamond and our father. But now that you have so foolishly escaping I shall duel you!
Ernie: [ignites his sabers] Is that right?
Princess Celestia: [ignites her lightsaber] YAAAAAAAAAAHHHHH!!!!
[They clash their sabers in different angles]
[the 3 combatents continue clasahing their sabers as them come onto the outer walkway of the airship, and come into a blade lock, but resume clashing sabers, and the 2 royal sisters Force Leap back onto a pile of crates]
Ernie: [cackles as he Force throws some broken bits over to them, as they leap in seperate ways to avoid them as Ernie continues throwing several browk bits of walklway at them as they jump to avoid each one]
Princess Luna: [stops in her tracks and clips her saber back on her belt]
Ernie: [then Force throws a ciculiar object at her, but she catches it with the Force and slowly starts it spinning and then throwes it back] Oh no. [it slams into him and sends him flying off the walkway and onto the crate where Solar Flare is.]
[then the 2 Force leap down and ignite their sabers again, but Ernie then fires Force Lighting at them which they block with their magic as they clip their sabers back on their belts and the 2 sides push against each other, as Celestia and Luna then start drawing the Force within their magic beams and then it starts fighting back against Ernie's Force Lightning until it reaches him and it explodes, sending him flying back and onto his back]
[then the 2 charge him and rise their sabers ready to strike him as he reignites his own and blocks theirs as they are in another blade lock, and slowly Ernie gets back on his feet and starts pushing them back to the edge as they are inches away from falling off]
Princess Luna: RAAH!!! [slides underneath Ernie and she swing sher saber up and destroys the Lightsaber in Ernie's right hand]
[the 2 halves of broken saber fly back as the now fading blade hits some of the chains holdiong the crate and they fall into the cliff below.]
[Ernie then furiously clashes Sabers with Celestia's as she blacks ever swing as they approach the other edge of the crate and they come into a blade lock again]
Ernie: You can't beat me, Princess. You're weak without you're students! I will have that diamond in my grasp!
Princess Celestia: [grits her teeth as she strains against Ernie but then she gets an idea and unholsters her revolver]
[we then see Celestia pointing her gun at Ernie's abdomen as she fires 3 more shots into it]
Ernie: AAAH!! [he then walks back holding his abdomen as he the drops his saber which extinguishes its blade]
Princess Luna: [holds her own saber at Ernie's neck]
Ernie: You're gonna strike me down? It's not the Jedi way, you know?
Princess Luna: Yes, but only in anger. But I'm not anger. So I'm not killing you in anger, I'm killing you in Justice! [swings her saber and slashes his chest]
[but then another rocket hits the ship causing it to lopside and which the 3 slide down the top of the crate and whilte the 2 alicorns grab on, the now beaten Ernie slides off and fall into one of the propellers!]
Ernie: [yells as he then killed by the prop]
[Then, the chains holding the crate break.]
Princess Celestia: Hang on!