Diablo Crossover.

The Archangel of Justice destroyed the Worldstone to spare Humanity the corruption Baal infected it with. The force of its death knell shatters Mount Arreat and sends Tyrael hurtling across the endless planes of reality. He falls upon a world untouched by Angel or Demon, far from the sight of the High Heavens. So far, in fact, that he fears he will not be reborn from the Crystal Arch.

Wounded and near death, hope appears in the form of two strange creatures bearing the power of night and day.

Tyrael now faces a time of recovery as his power slowly heals within a body fashioned for him by his saviours. Justice Incarnate tastes for the first time the life of a mortal, and it is a strange, confusing experience .He has been left in the care of one Twilight Sparkle to learn of this world.

After all, where better to find peace and harmony than Ponyville?

Act I - The Root of Evil
Act II - ????????
Act III - ???????
Act IV - ???????

[Cover image used with full permission of the owner. Go on, go have a look at Chagial's stuff.]

When Celestia went on sabbatical into the west, she promised Twilight it would be only a couple of months. A year and a half later, the sun resists control, the country is in ruins, and her teacher is lost in the wilds. Twilight has become the apostate, her faith in her teacher and her teachings waning. In the wake of tragedy, her resentment blossoms into fury and she vows that something must be done. Shadows gather around Canterlot, and old things that should not have been awakened are on the move. The Student goes west, her hope restored by friendship and righteous fury.

The night, at long last, is passing.

Twilight becomes alicorn of the stars. This is sort of a problem, because Luna kind of already was alicorn of the stars. Oops!

TV Tropes

Things are hard in Ponyville for Fluttershy and Discord; mainly because of Discord. But when magic starts to go on the fritz and eventually starts failing altogether, it's up to the main six and the Draconequus to find out what's causing it and, more importantly, how to fix it.

This would be a lot easier if anypony trusted the King of Chaos to begin with, but with bigger problems on the horizon, some things will have to wait to be dealt with. Like trust. Or loyalty. Or friendship.

Of course, sometimes what we think isn't important to deal with right now, is exactly what's needed to prevent things from getting far, far worse.

When Twilight plays with magic beyond her control, she finds herself and Rainbow stuck in a strange, horrible world. When they find out what happened, will they be able to get home? Will they even want to?

This story is a sequel to Princess Twilight Sparkle's 500th Birthday

Five years have passed since the events of that fateful morning. Smarty Pants and her friends set off on an adventure of a lifetime to discover the secrets of the past when they awaken a… oh wait, that would be spoiling it!

Many questions from the first story will be answered! New questions will arise. Lunch will be had, pies will be thrown, blood will be kept inside bodies because seriously, ew blood, you guys.

Notes:
- Cover art commissioned by HAK2. Check out his other stuff, too.
- This is a story in the Birthdayverse.
- This story was written and completed (except for the epilogue) before Season 4 of MLP:FiM aired.
- Many thanks to my faithful Pre-Reader and all around super-duper best pony, Blood Lord go read his story, too!

On a dark night filled with even darker magics, an insane cult attempts to give Nightmare Moon a body and life of her own, utterly separate from Princess Luna. But, when the spell is interrupted by Celestia, something unexpected is created.

Now, a little black alicorn filly named Nyx finds herself living under the care of Twilight Sparkle, only to be haunted by memories and emotions from her past. Is she Nightmare Moon reborn or is she simply a doppelganger with a soul and mind of her own? Can Twilight Sparkle protect Nyx from those who refuse to see past her dragon eyes and black coat?

Or, will Nyx be forced to inherit the sins that may not even be hers and become the greatest evil Equestria has ever known?

"The pieces are set, and the dice are in play. But does every pony have the heart for this day?"

Nearly two hundred years have passed since Rarity Belle merged with the Crystal Heart and took the throne of the Crystal Empire. Since then, through her care, determination, and vision, the Empire has flourished like never before. Now Empress Rarity stands as not a ruler of a providence, but the monarch of a rising superpower.

Today though, is the Empress' Birthday, and Lady Merry Sapphire, seneschal to the Empress, is determined to make this the best birthday Rarity has ever had. Little does she know that not everypony shares her enthusiasm for today...

Notes:
This is an official prequel to the Princess Twilight Sparkle's Birthday stories, created by Autumnschild. This story will develop and expand much of the world we made, but taking place 250 years before PTS500 and its sequel, PTS505. Due to its time gap and status as a prequel, you do not need to read the stories created by Autumnschild, and I have done my best to help that. However, knowing what happened in them will help you be a bit more aware of what is going on, and I encourage you to go read them for they are very enjoyable.

We now have our own group! Come check out the Birthdayverse!

Credit goes to Autumnschild for the proofreading for this story.
Razalon The Lizardman is credited for the grammatical overhaul.

Great thanks goes to these two, for this story would not be as good without them.

Ace was a street magician with a lucky streak. His luck was legendary among casino owners and fellow magicians. Any risky trick would succeed flawlessly and any gamble would pay off for him.

After performing his greatest and final trick he is brought face to face with the entity responsible for his incredible luck. The goddess of fortune herself. Lady Luck.

She offers him a deal. To become her champion, her Wild Card, and go to Equestria to spread luck among those who need it the most. So he finds himself in a magical land, in a new form, and ready for anything that comes at him. To a reasonable degree.

(Part of the Chess Game of the Gods universe created by Rust and BlackWing)
(Cover art by Grusborg on deviantART)

Many years after sending her beloved protege to Ponyville, unease sits heavily on Princess Celestia's heart as her relationship with Twilight Sparkle seems to have cooled despite all they've accomplished together. On the advice of her sister, Celestia sets out to investigate and resolve the lost connection with her most faithful student. What does it mean to be a Faithful Student...or a Princess of the Sun?

Earned a six-star rating on Equestria Daily and featured on its very own TVTropes page!.