Operation Resurgence

Arrival
The goal of Operation Resurgence was to breach the shield of The Forbidden City, make the way inside, and retrieve the Elements that were believed to be in the largest temple located in the city. Caprice was the only reason the Equestrians got through, or even knew about the Elements there.

Equestria's monarchs, who were princesses at the time, joined in on the battle themselves due to its importance. A mere twenty helicopters transporting the mane six, Celestia and Luna, the anti-six, and various White Army and Night Corps specialists flew straight there from Canterlot without stopping. Over the course of the 12-hour flight, they refueled twice mid-air using magic and spare fuel tanks they brought along with them. This was the much wiser alternative to teleporting directly to TFB, since Death and his army was believed to already be there.

Upon arrival, the first thing the Equestrians noticed was that one of Death's "armies", almost half a billion in number, had completely surrounded the city and were trying to break in. Upon spotting the incoming helicopters, Death's general, War, sent hundreds of thousands of birds to fly directly at them. Even when using magic to repel the birds, there were simply too many.

The Equestrians barely managed to reach the shield in time before the entire fleet crashed in the ruins of the city, passing through the shield with Caprice's help.

Day one
It took an entire day for the scattered survivors to regroup. Over the course of that day, billions of birds were beginning to flood the sky over the shield in order to render the inside pitch-black. Twilight Sparkle, the mane six, the anti-six, and the princesses made camp for twelve hours inside a coliseum-like structure for the stragglers to get there. The camp was magically lit with magic. The actual camp was made dim, while the areas surrounding the camp were brightly lit. Every Equestrian took a shift sleeping and watching guard during this period.

Just before moving out, the small force was attacked, in great number, by humans using spears and bow and arrows. Only two ponies were lost before the humans retreated. Once the Equestrians moved out heading for the temple, leaving behind magically-protected weapons and other supplies for any of the 15 other missing soldiers, the humans attacked them from a distance. They did not let up throughout the entire trek, despite their lack of success.

A few miles before reaching the temple, the prehistorically-equipped humans were engaged by another, unknown source. They were engaged by other humans who used firearms and rode horses. After a brief stand-off and some careful negotiation by Celestia, these more advanced humans agreed to take the ponies to their city. Along the way, the princesses carefully explained their mission to the humans, who agreed that their leaders would be willing to help.

Upon reaching the massive, protected main gate, the humans that accompanied the ponies explained where the found them and what happened, and what their goal is. After several minutes of waiting, they were allowed inside the gate.

It was nearly midnight inside the shield when they got there, though one would not be able to tell because of the birds.

Day Two
The Equestrians were met with interest, since the plain horses inside of the shield are unintelligent. The mayor and sheriff of the human capitol, Calvin, met with Celestia and Luna, and agreed to help them, saying he knew exactly what they were looking for. No one had ever been able to touch the "light stones" because there was an invisible barrier protecting them. The temple was within easy reach, since it is inside the gate.

While agreeing to cooperate, Death managed to do what thousands of powerful magicians throughout history could not - break through the ley shield around the city. The billions of birds swarmed in to kill and infect. While on the way to the temple, the one tank the Equestrians brought - piloted by the Crusaders of Harmony, fell through the ground into a an immense tunnel. In order to survive, the Equestrians evacuated into that tunnel. They only managed to let about 200 humans in before they were forced to further collapse the tunnel to barricade the entrance.

The Crusaders led the way through the tunnel with the large spotlights on the tank. Several White Army unicorns brought up the rear, using magic to light the area behind them, since they were passing many other, smaller tunnels. About 3/4 of the humans were armed, so they were ready to combat anything they'd find down there.

Shortly after barricading where they entered the tunnel, the survivors were attacked by a sub-human race of humanoid monsters that had sharp teeth and actue senses of hearing and smell, since they were blind. They, like the other huamns on the surface, used spears, bow and arrow, and other melee weapons. They swarmed the survivors but did not stand a chance since so much of the tunnel was lit up by the tank, the gunfire, and unicorns.

After repelling the attack, the survivors made camp in a massive cavern, in dire need of rest.

Day Three
The ones who managed to catch some sleep woke up to the sentries' shouts of an impending attack and to gunfire. The camp comes under attack by the same sub-humans that attacked them earlier. After again repelling the attack, they continued onward in the largest tunnel they could find connected to the cavern. After traveling just a short way, Death's birds found them. They were forced to leave 40 infected behind. They were honored as heroes.

Shortly after they were forced to collapse that tunnel with tank fire. Celestia ordered the collapse of every visible tunnel, so long as there were at least two visible so that they didn't trap themselves. In continuing on this way for several minutes, they found an underground entrance to the temple they needed to enter. The Crusaders turn their tank around on Celestia's orders, getting ready to repel any further attack.

The mane six and anti-six venture into the temple to look for the Elements with Twilight Sparkle leading the way. They encountered a massive room with what appeared to be a bottomless pit with a very thin path leading up to a pedestal in the middle. On the pedestal was a golden bowl with all of the elements inside of it. For some reason, the ponies could all see the barrier and could easily pass through it, while all previous humans not even see it - much less pass through.

Right as Twilight was about to simply bring the bowl over with magic, all unicorns were suddenly incapable of casting any sort of spell. Two massive cerberus dogs began to climb up from out the pit. The door behind our heroes was barred shut. They were caught in a trap.

Before the dogs even climb over the edge, Daring Do swoops in and shoots one in the back of the torso with her anti-material rifle. She lands in front of the ponies in a dramatic fashion, shooting the other as it climbed over the side of the pit.

Exfiltration
The ponies returned, as fast as they could, back to the main body of surviving humans and ponies, who came under attack from Death's "soldiers". With everyone present and the elements handy, Celestia, Luna, Twilight, and every other unicorn contributed their physical energy in order to teleport everyone, including the present humans, back to rural Canterlot. Some unicorns die in the process, their energy consumed by the power it costed to transport that many bodies over thousands of miles.

Celestia, Luna, and everyone else who accomompanied them had only been gone for three days through their own eyes. To the rest of the world, they had been gone two months.

The now-endangered humans are taken into custody by the White Army and put on a base for their own protection.