The sudden split in the forces of the changelings and the subsequent combat between the new faction and the old definitely tipped the balance of the scales of the battle in the direction of the ponies. And despite how surprising it was, they adapted pretty well, giving support to the new colorful changelings and taking advantage of the enemy confusion to reorganize themselves.
However, King Thorax was unable to help, because very little time after giving his orders, he found himself in a fight with Queen Chrysalis.
The start of the fight was particularly interesting, as the changeling king knew he was going to deal with her fairly soon due to his daring to steal some of her changelings from her. As such, when Chrysalis appeared with a snarl in a violent teleport that made the air scream, Thorax was already prepared, and immediately caught her with his telekinesis (his extra horns helped a lot with that) and pushed her up with full strength.
The result was that Chrysalis was slammed through the thick layer of the roof of the base, making a direct path to the outside. Thorax immediately teleported outside as well to continue the battle.
His first movement had been very deliberate. Knowing how angry Chrysalis was likely to be, he decided to force her outside to protect the changelings and ponies from the aftereffects of the battle, changing the battlefield to a place with no one to harm.
It turned out to be a fairly wise decision, as Chrysalis' next move after he appeared was to unleash a combination of unicorn and pegasus magic by creating a tornado made of fire that she threw at him.
Thorax could have simply blocked the attack, but that approach was too passive and would give too many advantages to Chrysalis, he decided instead to run at the tornado of fire, layering as many shield and cold spells on himself as he could on short notice, in order to pass through the danger zone to rush at Chrysalis.
Turning into a rhynoceros at the last moment, he tried to gore the monarch with this horn, but she teleported at the last moment and appeared behind him. And then, with a wave from up to down, a wickedly sharp scythe blade formed from her hoof and tried to cut him apart, but Thorax turned into a small hawk at the last moment and avoided the cut by a small margin with a desperate dive.
Turning back to normal after that, Thorax tried to use his telekinesis to pull her towards him and hit Chrysalis while she was disoriented, but having experienced his telekinesis once, Chrysalis managed to free herself with an omnidirectional pulse of magic before she got close enough. Then she shot him with a freezing spell to hold him before shaping a leg into a piledriver to hit him with.
But Thorax reacted faster than she expected, turning into an elephant to break out of the ice prison and hitting her with his trunk, but then Chrysalis' shoulders sprouted blades that cut into the trunk, forcing Thorax to revert, but he turned into a crocodile and tried to bite her, but Chrysalis turned her wings into spears to pierce both sides of the mouth of the crocodile...
And the fight went on, with both of the Changeling Monarchs using a lot of pony style magic but making a lot more use of their natural changeling transformation skills. Chrysalis preferred to mold parts of her body, while Thorax was better at full transformations. And it didn't take long for a pattern to emerge, Chrysalis was doing more and more damage to Thorax, predicting his moves better and being hit far less often.
Thorax was only a newborn changeling king, while Chrysalis was a lot more experienced, and as she managed to start getting control of her rage, Chrysalis could put her superior experience to good use, to the point that she was dominating the fight and could win at any moment.
And just as expected, she did. Hitting him with a binding spell that trapped him in a multitude of chains, Chrysalis then turned her front legs into an immense hammer, that she raised up, empowered with a violent amount of magic and then swung down like the blade of an executioner. Thorax tried his hardest, but he had only managed to get rid of most of of the chains (the spell suppressed his ability to teleport) before he was hit.
The newborn changeling king fell down like a meteorite, hitting the roof of the base and going through it in a vicious reversal of his first gambit in the fight, before crashing down in a relatively empty area of the battlefield and creating a crater.
But even as he felt the aches in his body, even as he looked at Chrysalis up above, preparing herself to finish him off, King Thorax wasn't worried.
Chrysalis charged her magic perhaps more than necessary, but that was exactly what that usurper deserved! She was ready to rain down annihilation upon him and scourge even his memory from existence...
A ballistic pegasus rammed into her.
Yes, King Thorax wasn't worried. From the beginning, he already knew that Chrysalis was an opponent too powerful for him to defeat. But he didn't need to defeat her. Different from her, he had allies who could help, powerful allies who could be counted on.
The Knights had taken over the fight.
All he had meant to do in that fight was wound Chrysalis enough, exhaust her enough, that the Knights and Squires would have a better chance of winning against her.
A group of his changelings came to stand around him, guarding his fallen form from whatever enemies could come. The changeling monarch then decided to tie up a few loose ends, and used the newborn network to send a message to a few of his changelings to go all over the base and free every single being that had been trapped for use as a love battery by the changelings.
And he sent another one of them in a special mission.
It didn't take more than two minutes, and the changeling returned with the Crusaders.
He smiled at them "Hello, you three. Thank you for your help."
The three fillies blinked and were unable to react for a moment, Scootaloo was the first to recover "You're... Thorax?!" She exclaimed.
"Indeed I am. And congratulations on your new cutie marks, by the way." he spoke calmly.
"Wha- new?" Applebloom spluttered.
The three fillies looked at their flanks.
The subsequent squeal of joy knocked out Thorax for a moment.
"Okay. Those marks are cool, but what do they actually mean?" Sweetie Belle asked.
It really wasn't clear just from looking. All three marks were pretty similar, featuring the same tri-colored shield (red, pale grayish rose and grayish purple) with two shapes inside it and each other. Applebloom had a heart inside of an apple, Sweetie Belle had a musical note inside of a star and Scootaloo had a lightning bolt inside of a feather.
"Well," King Thorax started, attracting their attention "You helped me see the path, helped me fulfill my destiny, achieve my best... Maybe your marks are for helping others find their destinies."
The three looked at each other, Applebloom grinned "Well, I think that sounds like a lot of fun, but what do you say?"
The other two grinned at her.
"CUTIE MARK CRUSADERS, HELPING OTHERS!"
Trixie knew that Chrysalis would try to kill the newborn changeling king as soon as she got the chance, so the unicorn decided to prevent her from getting that chance. Thankfully, the fight between the two had given her enough time to charge one of her Spheres of Charge by using the magic container Pinkie Pie had brought. So, as soon as Rainbow Dash hit Chrysalis, Trixie prepared and cast a particularly powerful spell.
"This place is no longer part of the world...
"Perfect Illusion: Isolated World!"
This was one of Trixie's costliest spells. Even with the support of the Sphere of Charge, the show mare still had to spend two whole seconds charging to obtain enough magic to actually cast it. The wave of magic spread to an area that would become the battlefield, one containing only the Changeling Queen and the eight ponies.
And then, it fooled the world itself. It forced the world to think of that area as something that wasn't connected to itself, thus separating the arena from normal reality.
It had limits, only being able to fool the world for two minutes and needing the caster to be on the same patch of isolated world for it to work. But its virtues were equally apparent, it didn't need to be sustained, leaving Trixie open to do other things, and it was very hard to dispel by any means other than simply waiting it out.
It was the perfect spell for that situation.
Chrysalis barely spent a second stunned before casting a spell that threw several magical arrows at Rainbow Dash and bucking backwards with a leg shapeshifted into a spike, almost goring Pinkie, who had shifted behind her and attempted a punch.
"Wind Sword Style: Wind Cage!" And Rarity turned all the air around Chrysalis into a rushing maelstrom keeping her pinned.
But it didn't even last half a second, as Chrysalis shapeshifted her wings to triple their original size and gave a mighty flap, disturbing Rarity's control of the wind with sheer strength. Then Fluttershy reached her side, having ran over with a cheetah animal spirit, before trying to claw her. But Chrysalis grew separated armor plates to defend herself, before making a scorpion tail out of her own and trying to sting Fluttershy.
"Chaos Magic: Hungry Earth!" Twilight's spell got there just in time.
Striking the ground, it created dozens of huge mouths made out of earth that attacked Chrysalis, one of which managing to bite down on the tail. Dismissing that transformation (she had done the same for every transformation as soon as it served its purpose) Chrysalis released a burst of magic from her body that destroyed all the mouths, but during that time, Twilight and Fluttershy had joined hooves and prepared a spell.
"Duo Magic: Chaotic Butterfly!"
They released a dozen butterflies made out of swirling, chaotic energy, that flew towards Chrysalis. She jumped and flew to the air, releasing a blast of magic to destroy the butterflies. Sunset teleported right in front of her, already using her Trance Mode, and cast a powerful spell at point-blank range.
"Double Magic Enhance: Solar Sphere!"
A mini-sun that was still twice the size of the Changeling Queen hit her without giving her a chance to react. Causing an explosion that Sunset had to dodge by teleporting away. However, once the light faded it revealed that Chrysalis had only been scratched, due to increasing the thickness of her scales at the last moment. But she didn't look happy.
"Blast it! Why do they always throw suns at me?!" She shouted "See how you like it!" And she cast a spell that created a red sun double the size of Sunset's, and threw it at her at high speed.
The unicorn tried to teleport away, but suddenly Chrysalis' telekinesis squeezed her horn painfully, breaking her concentration.
"Merged Spell!" Twilight cast as fast as she could "Effect Sign: Reverse Target!"
And suddenly it was Chrysalis who was about to be hit by the sun. But she teleported at the last moment, appearing next to Applejack already slashing at her with a scythe blade coming from one of her hooves. The farm pony punched out right at the base of the blade, the point her Eyes told her was the weakest, managing to break the scythe. She charged magic into her hoof for a punch at Chrysalis' weak spot, but she grew spikes all over her body and shot them at Applejack like arrows. But Rainbow Dash suddenly appeared and carried the earth pony away from danger, dropping her off next to Trixie, before coming back at high speed.
"Rainboom Punch!" She shouted, punching beyond the sound barrier to create her special blast of magic.
Dash followed the blast with her hoof, forcefully putting more magic into it before the hit. But Chrysalis sprouted an immense claw from her shoulder that grabbed both the blast and Rainbow's hoof at the same time. The terrible impact made the claw crack, but it held, and Chrysalis reduced its size to bring the pegasus closer and try to gore her with her shapeshifted horn (it had three extra spikes), but Sunset teleported close and blasted Chrysalis with an overpowered fireball, stunning her for long enough that Rainbow Dash managed to charge herself with lightning to shock the changeling and escape.
"Duo Magic: Truth Seeking Arrows!" Both Trixie and Applejack shouted.
A dozen arrows of light shot themselves at Chrysalis, who teleported to avoid them, but the arrows teleported together with her, so Chrysalis grew a wide and thick shield from her right foreleg and blocked them...
And the fight kept going. With the Knights and Squires slowly realizing to their horror that, despite being weakened by the fight with Thorax, Chrysalis was still more than strong enough to take control of the fight. They used every single trick they had, combined attacks, sudden teleports, illusionary duplicates, Rainbow Dash acting as transport, Applejack pointing out weaknesses, Rarity's wind attacks, Pinkie's shifting, Sunset's brute force and all else they had trained together. But despite all of that, Chrysalis was getting increasingly close to taken one of them out of the fight, which would break the careful balance that let them face her. And they were tiring fast.
"Triple Magic Enhance: Grand Solar Seeking Blasts!" Sunset cast.
She created two dozens homing blasts of solar magic that attacked Chrysalis. But expending so much magic at once had been a mistake and Chrysalis didn't fail to take advantage of it, shifting to pegasus wings, she shed dozens of feathers that glowed with power and attracted the blasts of magic. At the same time, she teleported right in front of Sunset... And screamed.
The point-blank blast of powerful sonic magic broke through Sunset's boosted aura defences, cut into her body, caused internal injuries, made cracks appear in her bones and even shattered her internal magical formation, forcing her out of Trance Mode. Blindly, Sunset teleported away, trying to get time to patch herself up, and then shouted to the others.
"She's too strong! You five need to distract her!"
The five immediately understood, and Applejack took the first step, shouting to Chrysalis:
"Hey, Chrysalis! How's the family?"
The changeling queen immediately remembered about her recent loss, and snarled before flying towards Applejack, spells ready. But Rainbow Dash immediately flew over and grabbed the farm pony, flying at high speed and shedding feathers charged with lightning to slow Chrysalis down. The changeling broke through the feathers and summoned an entire plane of fire, ready to slam them, but then Pinkie was on top of her, punching with both hooves on her back and driving chaos magic inside her body, breaking her concentration (it tried to warp her insides into something useless, but her magic suppressed the effects automatically).
Chrysalis formed spikes to pierce through Pinkie, but she had replaced herself with a plushie version, which subsequently exploded into a shower of acid confetti. The confetti started eating through her scales, until she set herself on fire and burned it all away in a single blast. Then she noticed that an absolutely gigantic blade of wind had formed above her.
"Wind Guillotine!" Rarity shouted, making the blade drop.
Chrysalis turned her wings into a huge claw that snapped closed on the blade, breaking it but not preventing Chrysalis from being buffeted and cut by a huge blast of wind. When she recovered, the changeling saw Fluttershy right in front, Staring at her. But she only got stunned for a tenth of a second, before waving her right foreleg upwards while turning it into a pseudo-flyswatter, hitting Fluttershy and making her fly, before Rarity manipulated the wind to bring her out of harm's way.
And that was all that was needed, because the Knights were ready.
They had activated a fairly powerful Overdrive and prepared a combination attack.
"Power and precision, united in a single spell...
"Perfect Duo Magic Enhance: Ultimate Seeking Arrow!" Sunset and Trixie chanted and cast together, creating an arrow combining the best of their specialties, an attack covered in illusions that would prevent any detection, and powerful enough to cause heavy damage to anything.
But that wasn't all, because Twilight still had her part to do.
"Magic refined and perfected...
"Ideal Sign: Grand Enhance!"
That was their third ultimate combination attack, the one that had Twilight taking on a lead position. And her role was simple but effective: Using her conceptual magic, Twilight took the already masterful attack from her partners and enhanced it into an ideal state.
"COMBINATION ATTACK: SUPREME ARROW!" The three shouted, as the arrow became golden and then disappeared, seeming to hit Chrysalis almost instantly.
She gave a horrifying scream as the arrow pierced her body. And then the hole left by the arrow started shining with a light of pure destruction, and cracks started appearing on her body, and more light started to leak out from those cracks, until Chrysalis was shining brightly.
And then she exploded. Her entire body seeming to disappear due to the sheer power of the event.
The three Knights fell unconscious. Then their Squires relaxed... Until Applejack blanched.
A black hoof emerged from under the earth, and it pulled its owner out of the ground.
Revealing Queen Chrysalis.