Three days after the plan was made all of the soldiers from all of the other camps the princesses said they had all over Equestria had arrived, there were so many of them that it looked like an entire army up close and with the addition of the Changeling swarm it was an entire army. They had conversed with all of the different ponies to instruct them on what to do during the attack, they had instructed the Changelings to do whatever they could to help in the attack; they didn't really know what the Changelings could do in terms of fighting without the love they need to survive.
The captains of the pony factions all walked over to Princess Celestia "All of our troops are ready to move out your majesty." the captain of the Pegasi said.
"We shall move out as soon as you give us notice, ma'am." the Earth Pony captain said.
Celestia nodded "Good, we shall move out soon. We must begin the process of defeating Discord as soon as possible. Tell your men to get ready to move out."
"They are all ready now your majesty," the Unicorn captain said "we can move out immediately."
"Inform Queen Chrysalis that we are leaving." Celestia ordered. All three gave a hoof salute and walked towards the area of camp the Changelings had made their home.
***
The army marched towards the gates of Canterlot, Earth Ponies up front, Pegasi behind them, the Changelings second to last and the Unicorns ready to give magical support at the back. Behind all of them walked Princess Celestia, Princess Luna, Queen Chrysalis and the four time travellers. No one could escape the feeling of dread that had come over them, they were going to war with arguably the most powerful entity in the world that was not locked in Tartarus. They didn't want to admit it but they were scared.
They arrived at the gate and because of how many of them there were it didn't take long for a guard to show his face and ask them what they wanted, once he saw the army he froze. Just as he was about to run he was given a buck from an Earth Pony, as he was passing Doctor Hooves deduced that he would be out for at least a few hours just enough time he thought.
They continued to march through the city, knocking out any of the guards they come across. The citizens stared at them in awe as they went, no one could believe that someone was actually about to march into Discord's castle and try to take this city from him. It was unheard of before this.
After a few more minutes of marching towards the centre of the city they reached the corner beyond which was Canterlot Castle. The first of the soldiers turned the corner and saw immediately why they had encountered so few guards in their trek to the centre of the city, hundreds of Discord's guards were outside the castle. They had been expecting a fight.
Discord was stood on a balcony at the top of the highest tower on the castle, they assumed that it was his sleeping quarters but they were unsettled by one fact. He was smiling at them. Discord was stood on a balcony at the top of the castle, knowing fully well that they must have defeated Sombra to get there and yet he was still smiling at them. Confidence will be your downfall Celestia thought to herself.
Discord just continued smiling and staring but after a while that grin of his faded into an annoyed frown "Kill 'em!" boomed his voice and his army of black-armoured guards charged.
The Earth Ponies at the front of the army prepared for the charge of Discord's men and as the black-armoured ponies clashed with the forces of the Alicorns the Earth Ponies butted their heads up and the initial attackers were thrown off balance by the head butts. After they had knocked their enemies off balance the Earth Ponies charged forwards, hitting, kicking, sometimes even biting but they kept attacking in every way they knew how. It wasn't long before the Pegasi left the ground and were in the air dive-bombing Discord's army and assisting the Earth Ponies in trying not to die.
Discord's guards were being knocked all over the place by the Pegasi and Earth Ponies but for every one they knocked out or killed it seemed that two more would soon be moving in on them with murderous intentions. Chrysalis stood waiting patiently until she could see that the current forces were becoming insufficient and she yelled at her children "Time to skin those bastards alive kids!" and the Changeling hoard rushed forwards and began tearing throats with their fangs. Chrysalis watched her children work with a sadistic pleasure rising inside of her.
The Unicorns on the other hand had gotten to work even before Chrysalis, they had begun casting their magic shortly after the Pegasi started charging Discord's forces from the sky. They were using fire magic to keep the opposition as far away as possible, casting healing spells to keep the infantry troops as well kept as possible and were using magic blocking spells to keep the other army's Unicorns from aiding their own soldiers. The trouble was that the other army's Unicorns were doing the exact same thing.
Doctor Hooves and his three companions were watching silently from behind a building, it was far too dangerous for any of them to get involved. Not even Big Mac had been permitted to take part in the fight because while he may be strong he had no actual combat training so most of the kicks he used were only for using on apple trees. None of them liked the amount of death they were seeing but they had come to see history play out so that was what they were doing.
Even with the growing sadness within them as they were seeing so much death, they had an odd sense of enjoyment about the entire situation. They didn't enjoy all of the death, they enjoyed the adventure they had been on and for some strange reason they found themselves craving more; it honestly confused them. Doctor Hooves' interest was purely scientific and historical though, he had enjoyed this but he had thought that enjoyment came from the reliving of history and the scientific discoveries that might me made if they carried on to other places. The possibilities that ran through his mind were endless.
The battle continued playing out, Celestia and Luna watched sadly as so many hypnotised souls were slaughtered by their soldiers. They could also see that they were clearly winning and with that came a sense of hope which eventually replaced the sadness, they might actually pull this off. Discord was already looking aggravated by the scene which played out before him, he was losing. He didn't like losing.
"Shadow Pegasus," he said angrily. The shadowy pony stepped out from behind him and spread its wings, looking forward to whatever orders its master might give. When Discord spoke again he sent a wave of surprise through the otherwise emotionless Shadow Pegasus "go out their and let down your invincibility. I want to get their hopes up." While the Shadow Pegasus was shocked by this command he had no way of disobeying it, he flapped his wings and took to the sky, intent on soaring onto the battlefield and dying for his master.
He did exactly that. He did a loop in mid-air and swooped onto the battlefield, knocking down at least a dozen of the enemies guards in the process. It then did as Discord said and deactivated its own immortality and carried on fighting with the soldiers that had been brought there by the princesses who so foolishly thought they could defeat Discord. Despite getting rid of his immortality he kept his immunity to sunlight, he didn't want to make it too easy after all. That would make the plan too obvious. Although if he was being honest with himself, he wasn't even sure what the plan was. What would him dying actually accomplish? It seemed like an act of desperation.
The Shadow Pegasus kept flying around, landing and beating up on some of the soldiers and then flying around the battlefield again, he was wondering if he had made it too hard for them.
The Unicorns were trying desperately to make sure none of the main fighters died and when one of them saw the Shadow Pegasus he also saw how many of their stallions it was killing. In retaliation the Unicorn flared his horn with an orange light which erupted into flame, he let the flame fly towards the Shadow Pegasus and when the flame hit home the Shadow Pegasus went down like a sack of apples, landing on the floor next to a group of soldiers he had knocked down and were now getting back up. Once they had regained their senses they noticed the Shadow Pegasus slowly trying to rise. They looked down on him angrily and moved forwards, Discord could sense his minion's pain as the Shadow Pegasus was beaten to death.
Right then Discord thought, smiling now that I've got them overly confident it's time for me to join the fight. He let out a chuckle "This should be fun." he said to himself.
Before anyone was prepared Discord appeared on the battlefield in a puff of smoke, he mentally grabbed several guards and made a crushing gesture with his hand and the heads of the guards he was holding exploded in a shower of blood and brains. He did this to several more groups before Celestia and Luna walked through the carnage of the battle towards him, he smiled and bowed to welcome them. "I knew you would come back," he said "and I knew you would beat Sombra. The son of a bitch was plotting against me, all he wanted was power. I kinda liked him." Discord let out a chuckle "And now here you two are, you'll regret ever getting involved in my affairs Alicorns."
With that he threw a fireball that just appeared in his hand at them, he was determined to kill them and anyone else who wanted to oppose him. Celestia and Luna dodged his fireball and he threw several more at both of them, they dodged out of the way of every single one of them but Discord was still too confident to realise that they now had him cornered between the both of them. The necklaces they wore began to glow along with Celestia's new crown, Discord didn't know what it meant so all he could gather was that they were going to attack him. He laughed at them and stood there waiting for the attack to come, if he had realised what was happening he probably would have killed them both in a fair fight.
Beams of magic erupted from the necklaces and the crown and they hit Discord directly, he screamed with pain as he realised that this was no ordinary magic. He tried to run but his movements were sluggish, he looked down and saw his features turning grey, not just grey but to stone. He screamed in both pain and fear as his entire body was engulfed in stone and he froze in place with a look of sheer terror on his face.
In the moment when Discord became completely covered in stone all of his remaining soldiers passed out, upon closer inspection none of them were dead, just unconscious. Once everyone figured out what had happened there were cheers ringing up from all over the castle grounds, citizens from the rest of the city came out to see why there was cheering and when they saw they all joined in. Everyone was happy, but something was wrong with Luna.
As Celestia looked closer at her sister she saw the purple energy of dark magic radiating from her sister...