"There is Still Time, To stop the Key from Turning."

Chief led everyone out of the dungeons, into the openness of the castle's hallways.  He turned around and spoke.

"So, is everybody ready?"  All the ponies nodded,  "Good, now just follow me and stay in the shadows.  They can't see us very well when in the dark."

John lead them through over a mile of castle hallway until they finally found the front entrance to the castle.  The front part of the castle was scarcely covered with enemies, which made the escape much easier for the Spartan and the ponies.  John looked around to make sure nobody was looking for them yet.  Lucky for him, they were in the clear.  The Spartan opened the large front doors, creaking a little at the hinges.  What was outside the castle, was astonishing.  No shadow guards were to be seen, and the streets were completely oblivious to the evil taking place in the majestic castle.  John gave the all clear and led the out the last part of castle.

"No one, not one guard is here."  Luna inquired.

"That means that Entropy has not started his final push to take over Canterlot."  Celestia noted.

"That doesn't give me much time to do what I need to, but I will have to work with what I got."  John said.

...

John led the group of ponies to the downed Pelican he arrived in Equestria on. He opened the hatch and grabbed some spare magnum ammo and a storm rifle.  On his way out of the Pelican, John felt something stir in his head.  He passed it as a migraine and moved on.

"Alright, my plan is simple.  Sneak into Celestia's room, get the box, and bring it back here."  John ended his speech as quickly as it began.

"Is that is?"  Shining replied.

"Yes, and to get this show on the road, I need to go now-AHHHH!"  John's sudden outburst scared everypony in the vicinity.  John closed his eyes and looked through his thoughts, trying to see what was giving him pain.  The familiar face of Coratana appeared, but it wasn't normal, it was, red and angry looking.  As it appeared, it started to speak.

"So, John.  I guess I came at the right time, huh?" Cortana asked.

"Cortana, how are you here, you, 'died'?"  John asked.

"I guess that you can't really get rid of me.  However, I can't be here for long."  Cortana said.  "I know how to beat Entropy.  Now it's crazy, but It's the only other way besides the way the, local inhabitants would like to try."

...

John snapped back to reality, sending a shock down his spine.  He started gasping for air, and ripped off his helmet in the process of getting air.  For the first time while being in Equestria, John revealed his face to the ponies.  In the essence of  it all, he revealed that he was not only a machine.

"I must get to the castle."  John grunted through the pain in his throbbing head.   Soon enough, he started to sprint in the direction of the castle, leaving the ponies confused and alone.

John made the sprint between him and the castle as fast as possible.  Making sure he had the time to do Cortana's last wish.  And with his thoughts rambling through his head, John arrived at Canterlot's main gate.  This time around, the main grounds were not so peaceful.  Shadow guards filled the spaces where Celestial guards once were.  Blood splattered the walls, and dead bodies filled alleys from time to time.  John unholsterd his storm rifle, and aimed at the nearest Shadow guard, and with a pull of the trigger, he started a mass riot.

...

John took his knife out of the Shadow guards neck, blood falling from the tip of the blades edge.  Now that he was at the front doors of the main castle, John kicked the door open and stomped into the throne room, where Entropy was angrily staring at him.

"I trusted you John, and you lost it all."

"I was never with you."

"That's obvious, but what I want to know is, what, what is it you want?"

"I want you to leave Twilight's body!"

"Oh, so cliche, the hero comes in and demands his-"

"In exchange for my body..."

"Well, that's not what I expected at all, but your offer is very tempting.  What's in if for you?"

"Well, to begin with, I know you weren't working on a way home, because there is no way home."

"Clever, what did Celestia tell you that?"

"Yes actually."

"Hmm, well, since you asked."

Entropy left Twilight's body, and turned into a dark fog, creeping its way closer to John every second.  John braced his mind for the pain that was coming.  He clenched his teeth as the spirit entered his mind.  And with a scream of pain, John changed form from Enrtopy's corruption.

"Nice look by the way, you are the most handsome human I have evvvverrrr seen."  Entropy let out a cry of victory and walked back towards his throne.

"Not today!"  John shouted from behind Entropy's corrupt voice.

"What is this?!" Shouted Entropy.

As if on cue, Celestia and Luna trotted into the room, watching John struggle to walk towards them.

"Do it!" John then proceeded to pull out his magnum pointing it at his head.

"Nooooooooooo!" Entropy barked.

"Do it-"

John shot himself in the head, ending his life.  Celestia and Luna were shocked to see this, but were understanding to Entropy's control.  What they were unaware of was what was going on inside the Spartan's head.  Besides, they had to deal with the now awake Twilight Sparkle.

...

Cortana held John's hand, walking with him to his final destination spot.  They arrived at Reach, where he grew up.  What was in front of them, was Entropy's body, lying on the ground, twitching and spiraling out of control.  John took out his knife one last time, holding the spirit's odd form, and slitting his throat.  John took Cortana's hand, and they walked off together in his mind.

...

One Month Later

The memorial service was only held for the few that knew him.  The few that had the honor of knowing Equestria's new hero.  They all closed their eyes for their own respects, but in the midst of all the silence, there was a sparkling noise coming from Chief's armor, and for some ubseen reason, something hidden from the naked eye...

...he arose, and joined them in the moment of silence.