About a month later the Doctor was living in a small shop in Ponyville, making and selling clocks

It was surprising that he was able to keep still for so long, as Ponyville wasn't too eventful of a town, but it did have it's moments of chaos

Nobody was suspicious of him, so naturally he was able to blend into the town easily, and without incident he was now a pony of Ponyville

But something was wrong, he could feel it. There was a tang in the air, and this metallic tang told him that there was some serious energy being used, and in Equestria, magic was energy.

Now the Doctor was well aware he was nearby Twilight, but this magical energy wasn't common in Ponyville, and the Doctor ended up on edge

Every night before he went to sleep he checked on his equipment, the sonic screwdriver the fob watch and the psychic paper if he ever needed it

[…]

Celestia was speaking with Luna about what was troubling her

"The ruins were found a month ago, there is nothing to be worried about Tia" Luna said

"In the recent months there has been a large increase of magical energy" Celestia debated, "At the same time, the pictures that the group found..."

"It may simply be of something that his followers wanted to happen" Luna soothed, "As it has not, we can rest easy."

The doors to the throne room burst open, and a guard entered

"Princess" he bowed, "Your highness"

"What is it?" Celestia felt her gut drop

"I am merely to tell you that" the Guard removed his helmet, "It has returned."

Celestia nodded, "Send for Twilight and her friends, along with Doctor Turner."

Luna looked to her sister, "Are you sure this is wise?"

"Shining Armor and Princess Cadence will be able to hold it until they arrive" Celestia said, "But we have to be wary of those pictures, if that is what I think it is..."

Luna simply nodded

[…]

The Doctor was just waking up when there was a few bangs on his door, he knew that it was time something happened, he could literally taste it

The earth pony gathered up his stuff, the sonic screwdriver he grabbed out of habit, along with the psychic paper, but he ran out of time before he could grab the fob watch

"The others have already made it to the train" the guard sounded impatient, "We have no time for this."

The Doctor sighed, he could get the fob watch back before anything could get to it right?

But as he left the small shop he called home for a month he was left with a strange feeling he was being watched

[…]

The Doctor wasn't sure what exactly was going to happen, but he spied the element bearers on the train to Canterlot, appearing tense

Twilight was the tense one, while the others conversed about one thing or another, the Doctor opened a book about the magical artifacts said to be placed in Equestria

The ride wasn't too long, and the Doctor's need to move wasn't too harmed by the simple trip to the capital

Once they got to the city the Doctor and the main six appeared to be going down the same path, right before he got on the train the guard handed him a ticket for getting into the castle

[…]

Celestia was sitting on her throne when the Doctor entered the throne room

"Doctor Turner" Celestia said, "You came quickly"

"I wasn't given much choice" the Doctor said, "What exactly did you call me for?"

"Be patient Doctor" Celestia said annoyed, "My faithful student will be here when I explain."

The Doctor simply went and sat down

[…]

After an explanation to Twilight about the Crystal Empire, the Doctor once again got on the train in order to get there

He settled into a booth, and Twilight along with her friends were on the opposite of the train car than he was on

Before he could doze off a mare plomped down on the booth across from the Doctor

He got a look and recognized her instantly, it was Derpy Hooves

"Hey Doctor" she said in her bouncy manner

"Hey there Derpy" the Doctor didn't react too shocked

"What was your plan once you got to the empire?" she asked

"Investigate, and stop whatever's going down there."

"If you want, I know where to start looking" Derpy said, "Like you told me to do."

"Right then" the Doctor sat up, "Let's get right down to it."

[…]

The Doctor and Derpy exited the train, she lead him ahead of the others and into a strange shell that shielded them from the cold and the dark snow

"Nice place" the Doctor commented as he continued towards the castle

"Not that way" Derpy said, "We have to go this way"

The Doctor shrugged, and continued to follow the wall-eyed mare

It was a bit of a walk but the pair soon came upon a large pair of doors, there were sounds of a scuffle on the other side

The Doctor pressed his ear against the door, he could barely make out what was being said on the other side

"If you keep trying to do this, I'll have to stop you!" This voice had a proper accent, exactly the same as the Doctor's

It was then the next voice answered

"You are such a foolish pony, to try and stand up to me!"

The Doctor instantly felt a surge of adrenaline at that voice, he knew whatever that came from wasn't friendly

"I will have to end your puny life now!"

"Doctor, go and save him!" Derpy said urgently

The Doctor quirked his eyebrow, Derpy seemed quite focused about getting here and opening that door

"Alright, calm down." the Doctor said

He got a grip with his front hooves, then jerked his hind legs outward in a fashion similar to apple-bucking

The doors flew open, slamming as they revealed what was going on

On one end there was a stallion that mirrored the Doctor almost exactly in terms of looks, being surrounded by a strange dark mist

"Doctor!" Derpy called, he jumped out of the way of a massive blast

Whooves landed next to Derpy, they exchanged a hug

"I HAVE YOU NOW!" The voice sounded triumphant, and a small prick of a magic blast surged

Time seemed to slow down, Whooves and Derpy turned their heads

But the blast was blocked by a certain timelord

The Doctor felt the rush of oncoming pain surge through him as he fell to the ground, landing on his side

All sound seemed to fade from his ears, and his vision darkened as he tried to stay alive. The first sound he could hear was Derpy crying out in shock

The Doctor knew what was coming next, he was dying.

And this time he was out of regenerations

"So...this... is what... death is like..." his voice was labored, and pain was laced all over it

"Doctor, can't you do something?" Derpy asked

"No, he can't regenerate anymore." Whooves said

The Doctor sighed, this was it, his death had finally come in a moment of fighting for someone else

He turned his head towards the shadow, as it formed into an actual being

A unicorn with a pitch black coat and mane, his eyes were red with a green colored white of the eye, they gave off a purple shade

"He died for you" Sombra said, "A shame, and what a waste."

Whooves bent down, touching the Doctor on the cheek

There was a loud hiss, and a hoof mark was left on the part that Whooves had touched

"An artron energy spark?" Whooves pulled back his hoof quickly, "But that means..."

The Doctor looked at his hoof, a yellow mist was beginning to come off of it

"Derpy get back!" Whooves demanded

"Wha-? What's wrong?" Derpy asked, startled

"He's... I can't believe it..." Whooves looked awed

"I'm regenerating" The Doctor said, and then exploded into the yellow energy

[…]

There was a cry of agony, as he transformed into a new stallion, the Doctor pitched his head forward, the regeneration finished

He quickly did a once over of himself

"Ah! Four legs, and hooves. I'll have trouble flying the TARDIS with that" he said, "Still not ginger, I'm a pony and I'm still not ginger!"

Derpy and Whooves exchanged a look

"Light turquoise, a nice color" he looked at his side, "and wings! That'll be brilliant!"

"and this voice! Hello!" the Doctor finished, "Wasn't there something important we were doing?"

"I believe you were talking to me." Sombra said, annoyed

"Oh right, sorry there big fella." the Doctor said, "Who are you anyway?"

"My name is King Sombra"

"King Sombra" the Doctor repeated, "What do you have planned?"

"The crystal empire shall be mine, and it will do my bidding." Sombra said

"Ah, now there's where we have a problem." the Doctor's smile faded, "I may be brand new, but I know I would never have stood for that. In any of my 14 lives."

Sombra laughed, but there was a sound from outside the castle

"Hey! I've got the crystal heart!"

The Doctor recognized that voice as Spike, Twilight's dragon assistant

"That is MINE!" Sombra became shadows and rushed out the door

"Not if I can help it" the Doctor looked at Whooves and Derpy, "Thank you, but I think I can handle this one."

The Doctor didn't give them a chance to answer as he rushed out the door, after the dark king

"Do you think we've saved him?" Derpy asked

"His future will be very dangerous" Whooves answered, "We simply let him live to meet that fate."

[…]

The Doctor caught up to Sombra as he almost got to the crystal heart

"Stop right there!" the Doctor stood in the way, "I won't let you near that heart!"

Then an image popped into his head, the picture in the ruins

The shadow unicorn, the pegasus, the shattering heart

"Here's a challenge" the Doctor said, "I'll run, and you try to shoot me, if the crystal ponies can activate the heart before I die I win."

"And if you die?"

"I'll do my best not to" the Doctor said, "and GO!"

The Doctor threw himself to the side, bobbing and weaving as he tried to avoid getting hit by the shadow king

Right when he thought he was getting used to it the dark crystals burst from the ground, the Doctor flapped his wings in order to gain air

He could see the crystal ponies charging the heart, and Sombra exploded

Not turned to stone, but crystallized and shattered

*best way to kill something in mlp*

The Doctor touched down on the green grass, smelling the clean air of a newly freed country

"Who the hay are you?" a rainbow maned mare appeared behind him

"I'm the Doctor" the Doctor said

"Doctor who?"

"It's just the Doctor" the Doctor said, "Allonsiro- you know what? How about adelante?"

"Ade-what?" Rainbowdash asked

"It's Spanish, for 'forward'." the Doctor said, "New Doctor, new catchphrase, new sonic screwdriver and new universe to explore."

"'the Doctor'" Twilight repeated, "That sounds familiar"

"I'd expect it to" the Doctor said, feeling a twinge of sadness, "Anyways, I'll be off."

"We never got to thank you" Shining Armor said

"And I'll never ask you to." the Doctor then turned and walked away

[…]

The Doctor entered the shop, it was dark and abandoned, he went upstairs to collect the fob watch before he left

He picked it up, but the watch was incompatible now, after he regenerated his whole mindset changed, and the body inside the watch perished, but the Doctor was able to get out the dark red bowtie

He put on the bowtie and fedora, it was a shade darker than the light brown poofy mane that he now sported

"Goodbye 13th Doctor" the Doctor said, "I will remember you."

[…]

The Doctor ran around the TARDIS, which had compensated for his now lower height and hooves in pony-friendly controls

"Right then, adventure is waiting!" he released the handbrake, "Adelante!"

A/N: It was tough decision to have the Doctor regenerate, but I thought it was about time that I changed things a bit more. A big thank you to... you. You've likely ready through a lot of crap to get to the good parts of my writing, and I hope you and I have had a good run. I'll be seeing you again in TARDIS ADVENTURES season 3