The Doctor looked out of his window at Ponyville. The cool night air blew at him, chilling him slightly. He looked at the bed he had once shared with Derpy. It now lay empty and unkempt, devoid of his love forever. His normally well shaven chin was covered in stubble, and empty cider jugs lay around his floor. He had had a purpose, traveling throughout time. But he had made a mistake. The mistake cost him his life with Derpy, and as such, he lost all sense of responsibility. His friend Roseluck checked on him constantly, but the doctor still felt hollow. Empty inside. His soul was being eaten away by the emptiness that only losing one’s true love can cause.

As he prepared to open a keg of cider, he heard somepony knock on the door. The Doctor walked over, only to find some pony he had not seen in some time. The pony’s long mane, a bright white that made him look old beyond his years, in the moonlight was a little calming to The Doctor. The pony’s dark blue body made him blend in to the night.

“ What do you want from me, Edrick?” The Doctor asked.

“I need you to go back to traveling. Gallopfrey needs you.”replied Edrick gravely.

“I can’t. After what happened to Derpy, I can’t bring myself to even look at the TARDIS anymore.”

“You must. Without you, Gallopfrey is doomed to the Daleks.”

“I couldn’t even protect Derpy. How can I save Gallopfrey if I couldn’t even protect one Pegasus pony?” The Doctor shouted, angrily.

“Look at me, Time Lord. What happened to Derpy wasn’t your fault.” said Edrick, his horn casting blue magic to turn the Doctor towards his face.

“If I hadn’t brought her with me, she wouldn’t have been trapped in the ice prison on Karotock, and wouldn’t have frozen to death. At least, that’s what I figured, I couldn’t find
her in the deep snow of her prison.”

“You can save her. Go into the ice prison and free her. Using the TARDIS.”

“Why hadn’t you told me that, you silly old unicorn! Let’s go!”

“I’m afraid I cannot go. Gallopfrey requires my aid. I have brought a friend of mine, who wishes to join your quest.” said Edrick.

As Edrick said that, a pony walked out of the shadows. Her yellow mane contrasted with the darkness surrounding her, and her light turquoise body made her simply beautiful.

“Who are you?” asked the Doctor.

“I’m Lightning Dust. I've been a companion of Edrick's for a while now.” said the pony, with a smirk.

“Listen. You can save Derpy, and then help the effort. If you don’t help, the Time War will end with the Daleks’ victory.” said Edrick.

“What good will it do? What good will any of this do? I am not a warrior, I am the Doctor. I will not go to war unless I have to. You cannot force me. I am taking the TARDIS alone, and saving Derpy. That is it. After that, I will forget the Time Lords.” said the Doctor.

“I thought you would say that.”
Edrick thrust a knife into the Doctor’s chest and quickly withdrew it. The pain. The horrible pain! The Doctor began to crawl.

“How is he moving? You hit him in the heart!”Lightning Dust screamed.

“Binary heart system. Two hearts. One was stabbed, the other has been broken!” said Edrick as he tossed the Doctor in a mirror across from the bed. Edrick forced a brew
down the Doctor's throat. The bitter yellow liquid went down surprisingly easy. Edrick grinned.

“Don’t worry. Once Gallopfrey is saved, I have a way to rectify this potion, and turn you back into your previous form. But now, a regeneration is being forced, and this particular regeneration will be a warrior. A powerful, willing warrior.” said Edrick, running the knife along the Doctor’s neck.

The Doctor began gasping for breath, trying his best to stop the blood flowing from his neck wound, but failing. He felt the familiar glow emanating from his hooves and head. The pain began to fade. He struggled painfully to stop the regeneration, but his efforts were in vain, the regeneration already beginning.

“No. What have you done? Damn it, Edrick!” The Doctor screamed.

“I did what was necessary for my planet’s survival.” said Edrick.

The glow consumed the Doctor. The force of the blast burned a hole in the wall and the bottom of the mirror that the Doctor had crashed into. The light began to fade, and from it emerged a different stallion. Over his previous hourglass cutie mark was a long sword. His mane was now a faint yellow, and didn’t extend down his neck unlike his last mane style, and was slightly neater. His eyes, a dark blue, was much darker than his body, and long wings extended from his sides.

“So, Doctor, how does power feel?” said Edrick.

“I am the Doctor no more. I am the ultimate warrior, defender of Gallopfrey. I bow to no kings or queens. I fear no shadows or death. My allegiance only lies in my best interest. I am the last hope of the Time Lords. I am the one hiding among the weak, yet towering over the strong. I am a fighter!” said the new stallion.

“What is your new title then?”

“I am the Assassin. And not once will I let anyone stop me from achieving my goals.”

Edrick smirked. He had known that the solution was able to force a Time Lord into becoming a warrior, but not a warrior so strong that even Edrick would fear him.

“What areas of combat shall I train in, Edrick?” the Assassin asked, interrupting Edrick’s train of thought.

“Well, stealth and sword combat seem good fits for you. Aerial combat would work well with the new wings.” Edrick replied, rather unnerved by the raw power that the Assassin seemed to release with every breath.

“Well, what weapons am I to work with?” asked the Assassin.

“These will work nicely, I think.” answered Edrick, opening a case. A cloak, white with a white hood and a leather cuirass lay within, alongside two gloves with small blades attached, and two long, beautifully crafted swords.

“Well, looks like this stallion is going to have some fun. Come, Lightning Dust, I have the love of my life to save.”

Author's Note

This is an Assassin's Creed, Doctor Who, and My Little Pony crossover, if you're wondering as to why I put the Crossover in the tags.