A League of Legends Crossover.
Mordekaiser, a fabled champion of the League of Legends known for manipulating pain for his own benefit and his enemy's downfall. Portrayed as a frightening being covered from top to bottom in sharp metallic armor while wielding a giant spiked mace as if it were nothing. So it makes sense why his arrival into Equestria through an error in the recalling system might make some ponies uncomfortable. They should be, because he doesn't like this place one bit and wants to go home at any cost.

Either he can be granted the penance of returning to Summoner's Rift to inflict his torment upon his enemies or he could stay in Equestria and do the same thing. Would that be enough reason to get the Kaiser of Morde back to where he belongs?

I'd heard about the TV show My Little Pony: Friendship is Magic from my college roommate who is way too into the show. Disturbingly so, actually, but good gravy I would never watch the darned thing! What am I, five? I've got better things to do with my time than watch a silly little girl's show. However, that didn't stop... something from transporting me into the world of the show, so here I am... in Equestria... trying to get home. This is gonna be interesting.

Special thanks to GuyFace, Jack Kellar, Storm Shaker, Spiffy McSquee, and Goober Trooper for helping me with this one!

This isn't where I belong. I left all this behind years ago, moved on with my life. But a mare from my past brought me back, and now she won't let me go. So I'm stuck here, trying to make the best of it with ponies that don't understand me, don't even like me. But when something moves in the darkness, and when things go wrong in the cold, dead night, they'll turn to me to try to set things right.

Why? Because once a police pony, always a police pony.
~~
This is a spin-off story to 'Why am I Pinkie Pie?!', and will contain spoilers for that story, but it's not necessary to read that story to understand this one.
Cover art by the talented Conicer
Need more Cinnamon Swirl? Merlos the Mad wrote a fanfic of this story!

There is now a side-story: A Hard Day's Nightmare Night

Isolated from her friends and taken prisoner in the middle of a war, Twilight must deal with the very real dangers of being percieved as an enemy as well as the nightmares of her arrival on 'Earth'. Can she overcome her own fears and the fears of her captors? Will the wayward unicorn's assistance be a boon or a curse to the 'humans?' Most importantly, will she ever find her way home?

"In short, it's a story of friendship and plasma rifles, with the emphasis on the friendship. The characters are well written, the XCOM setting is fleshed out very well, and the story is compelling. If you love XCOM, you'll love the story, but even if you've never heard of it, it's more than worth giving the first 3 chapters a read.

There's excellent action later on, but the real strength lies in the collision between the friendly and naive world of Twilight Sparkle and the desperate world of humans fighting a losing war for survival and willing to do anything to turn the tide."

--Arzoo

(XCOM/FiM crossover)
(Cover art commissioned by a friend and created by the magnificent FoxInShadow!)
(Original cover art by the amazing Carnelian can be viewed here!)
(Gore tag for blood and some violence)
(Many thanks to the studius OminousTen, Arzoo, xXFluttershyForeverXx and finally Setokaiva for giving my rambles a once-over)
(Now with it's own TV Tropes page! Get to tropin' folks!)

Wanted: Porter, assistant, jack-of-all-trades, minion. Applicants should be strong, loyal, pain tolerant, cold tolerant, unambitious. Must be capable of following simple instructions. Ideal applicant should be of low to average intelligence and mildly deformed, but exceptions will be made for extraordinary candidates, with extraordinariness to be determined by employer. Must be willing to begin work immediately.

Remuneration will be in the form of room, board, and insight into the true nature of the cosmos. Extremely generous bonuses up to and including subcontinents may be awarded if merited and if circumstances permit. Interviews for the position to be conducted at 108 Haybale lane at 10:00 AM sharp on 4/7. Applicants are expected to be punctual.

—The Dark Lord Sassaflash

Editing and indispensable writer-prodding by The Masked Ferret

Lyra thinks Discord is an idiot for not thinking to dodge when the Elements of Harmony were about to strike him. Discord thinks this is the perfect opportunity for a game.

Part of the Borderworld.

Now with audio reading by Dreamless Portal. Chinese and Spanish translations also available.

Death usually brings more questions than answers.

"Why did he have to go?" "When am I going to die?" "Why is death even a thing?"

Grieving the loss of someone close, one unicorn tries to unravel the mysteries behind life, death, and those who defy both. After all, why can't every pony live forever?

Featured by Seattle's Angels.
Featured by Equestria Daily.

Now available in print.

You'd think that being trapped in stone would mean that, if nothing else, I could get some peace and quiet. Unfortunately, it seems that Celestia has other ideas.

She has appointed these ponies... these 'Keepers', as she calls them, to keep me entertained during my incarceration.

Honestly? I'd prefer the boredom.

Cover art by matrosha123
Spanish Translation by SPANIARD KIWI found here

After a summoning mishap, six champions from Runeterra's League of Legends arrive in Equestria. At first, they are focused entirely on getting home, but soon find out that it might be more complicated than they thought when Discord decides that he can use them for his own ends. Continued in The Redemption of Jericho Swain

This story is a sequel to Broken Blossom

Joyous Blossom, the unicorn daughter of Sweetie Belle, is spared from death by Princess Celestia, and is instead given therapy to deal with her problems. What they don't know is that she is far beyond therapy, and she becomes more dangerous than anypony thought possible.

Now it is a race to prevent her from becoming her aunt, a task that is no easy feat. For Blossom is literally built to be the deadliest serial killer that Equestria has ever known.

Spin-off story to Broken Blossom which is a threequel to The Secret Life of Rarity

Cover art by the amazing Viofriedsebe