Long ago, the Seraphim granted power to the Doom Slayer that he might conquer the forces of Hell. The Doom Slayer has won, Hell lies defeated, and now he returns to the Seraphim's holy realm. His mission is not over though, he has promises to fulfill, rewards to collect, and as always, evil to defeat. Let those who would harm this sacred land tremble, for the Guardian of Equestria, has returned!

(This story now has two sequels: Legion and the novella Doom Slayer.)

It has been 30 years since Tirek was defeated. Now, after having traveled the world to regain his power, he is ready to conquer Equestria once and for all. However, the arrival of strange new outsiders threatens to bring Tirek’s plans to a halt. The fate of the world now lies with these strangers.

Now if only they could stop trying to kill each other…

(Picture source, image is not mine: here Prototype by MDreed)

Chapter 6 contains time travel, and foaling(mare pregnancy and birth)

Project Pariah, stuck in a cell, made by a virus, that pretty much sums up life for him, he has led a lonely existence, imprisoned and scorned for something that he didn't cause, because they are scared, what happens when you corner a fox? bad things.

They learned this with Alex Mercer and James Heller, both interests to Pariah, who can patiently wait, but when the End War breaks out and shit goes wrong, Pariah is thrust into a world he doesn't understand, but Parah is an adapter and can make himself fit in, but when he ha to reveal what he is, he is worried and hopes these inhabitants will not mess with things they don't understand... but in a world filled with peace, does it have a place for people and ponies like Pariah? Pariah who is lonely? maybe he can find company in a purple pony and her 5 friends, and 2, perhaps 3 Princesses and learn what it means to be human/pony...

Often called a psychotic, meth dealing hillbilly with a habit of untamed violence and murder sprees, Trevor Philips is someone that no one wants to mess with. The body pile he leaves behind and then sets on fire just for the heck of it proves that. But after a particularly deadly drug deal gone wrong, Trevor finds himself in a place even his disturbed mind has difficulty comprehending.

The feeling is mutual for the ponies.

A Spartan of the UNSC falls into Equestria and has various shenanigans in the land. First chapters revolve around how he meets the royalty, the mane six, and the new world in general.

A cold, calculating assassin is teleported to the magical land of Equestria due to the unstable powers of the siren, Lilith. Will our awkward, haiku-obsessed hero be able to adapt to the Magic of Friendship, or will he simply end up murdering everything in sight like he's used to? Let's hope its the former.
Only one thing is truly known, this was a challenge he was NOT prepared for!

Borderlands/MLP crossover. Challenge Accepted.

Cover art by steptrool on DeviantArt

After GLaDOS is uploaded into a potato battery, Wheatley humiliates the AI even further by uploading her into a project that was abandoned by Aperture a long time ago. In the blink of an eye, she finds herself in a deformed body of flesh and bone that resembles an equine, and is just as powerless as one too. It comes with all of its needs and bodily functions as well. To make matters worse, she's trapped in a land full of insufferable creatures that just want to make 'friends.' Will GLaDOS' cold, sadistic sense of humor and morals get the better of the ponies? Or will they peel away the once artificial being's metallic shell and find that there's a softer side? Probably not, but it's worth a try.

Story Theme: Tyler Bates - I Love You (Watchmen OST)

Thanks to Meeester, MrJoshy, and funkyferret for proofreading/reviewing.

Cover by Fedte16.