Unhappy that her future as a member of the monarchy is denied by Celestia, Sunset Shimmer escapes through Starswirl's mirror into another world, planning to take it over to prove once and for all she was fit to rule. What she didn't expect—besides a species change—was to arrive in a world already conquered.

TvTropes Page (Just created! Needs Help!)

Art (Will contain spoilers)

Sunset Shimmer - Bloody Sunset

Spoilers Ch. 11+: Angel - Angel and Sunny
Spoilers Ch. 18+: Princess - Comic
Spoilers Ch. 121+: Alejandra Acevedo - Flying at the speed of death
Spoilers Ch. 161+: Apple Bloom - Bloom
Spoilers Ch. 180+: Food - Sunset's Party Dress
Spoilers Ch. 185+: Fugue - Fugue by Rametep
Spoilers Ch. 197+: Exhausted

(Art is always welcome!)

WARNING: CONTAINS SPOILERS FOR THE WHOLE STORY: TIMELINE

During Nightmare Moon's escape from her lunar prison, by complete chance she accidentally free's another, alien, prisoner from his death sentence. However, when he crash lands just outside Ponyville, he sets forth on his prime directive:
The REGIS MK V will destroy all, none can possibly stand in his path.

While a diminutive threat at first, there is a reason why this nightmarish mechanization was about to be thrown into a black hole... and this world is about to learn exactly why.
~~~(Disclaimer)~~~
I did not create, nor do I own any of the characters in story.
Instead, Megas XLR (Produced by Cartoon Network Studios) and all characters referenced to, mentioned, or that may have appeared in this fanfic from said show were created and are owned by Jody Schaeffer and George Krstic

Coop is the expert pilot of a giant robot built for epic combat. His best friend Jamie, thinks he's an expert with the ladies.
Due to Jamie's big mouth and a not so gentle arrival in Equestria, it may take some time leave this strange colorful planet.
With M.E.G.A.S stuck in a new civilization to screw up, how will the ponies cope with the mayhem? Princess Twilight will certainly need the help of all her friends to watch over the human visitor who consumes all before him. Not to mention a red headed woman claiming to be the last human resistance soldier. At least the skinny jerk doesn't pose much of a threat, right?

If you haven't seen the show, this will still make some sense, but you should go watch it. If you don't like giant robots and screaming awesome then shame on you.

I do not own Megas XLR or My Little Pony Friendship is Magic. They belong to Cartoon Network and The HUB respectively.

"Living here in Ponyville
Fighting villains from afar
You've got to find first gear
In your giant robot car"

When the CMC stumble across a giant mecha from another time, another place, another reality, their latest quest for their Cutie Marks takes on epic proportions. Between getting to class, dealing with an angry alien that's somewhat friendly, dealing with an angry alien that is distinctly less friendly, and anything else the heavens can throw at them, you'd think things were hard enough. But they still have to be home by bedtime.

...at least piloting a giant robot makes it easier to get certain bullies to shut up. Ponies dig giant robots too...when its weapons aren't pointed at them.

Now where - and what - was first gear again?

Creative Consultant: The_Whovian16

XCOM Record: Operation: Rising Star
11:52 am, 18th Febuary, 2016
Northwestern Territories, Canada.

Summary: Witness reports contact with extra-terrestrial creature. X-ray is unconcious and unresponsive. X-ray does not match description of previously observed species.

Response: Strike-One dispatched on high alert, orders are to recover X-ray alive. Alien Containment prepared for the new arrival.

***

The war ended. They were beaten back, their mothership destroyed, their command structure in ruins. Lost ships and soldiers continued in vain, but thanks to XCOM, humanity won, and the world was saved. The Volunteer saw to that - everything changed because of one man.

And then suddenly, everything changed again. Only this time, it's not a man's doing - it's a mare's.

Proofreading by the aweome Setokaiva, entirely without me asking!
Tagged Dark and rated Teen: Gore, because there is going to be some blood shed by the end of this.

One pony's dream of meeting a human leads them to making a pact with Discord, but like such things always do, this brings about consequences that none could have foreseen. A dangerous enemy is brought to Equestria, and its minions are more than willing to begin exploiting this new world.
Elite XCOM operatives will have to work with the inhabitants of Equestria and beyond if they want even the slightest hope of slaying their hated rivals, and more importantly, to get back home.

After a two decade long hiatus the Warner brothers and the Warner sister are back and they have a plan to get back to the top. It involves a bunch of magical talking horses.

But how will the ponies react when the Warners attempt to steal their show?