MLP/Undertale crossover.
Not a PWNY-verse story.

Long ago, the Monsters and Humans fought a great war. The Monsters lost, and were sealed in the Underground. It would take the power of seven human souls to break the barrier that kept them imprisoned. They only had six. And so the Monsters waited and hoped, praying that another human would find their way to the Underground. Some thought the seventh soul would give their King the strength to break the barrier. Some dreamed of a human who would be their friend, and save them all...or had nightmares of one who would bring back the war.

...but nobody came.

...but somepony did.

Eons after the war, with no way to tell how much time had passed above, a tiny blue filly with wings and horn fell into the underground, calling for her Mama. None knew the poor creature's nature or origins...but her soul was powerful with magic, even more so than a human soul.

None can know what will come...of this little 'Woona'.

Cover art by Sanyo21

Being a Princess of Equestria is a hard and lonely job. Princess Cadance knows this firsthoof, and if it wasn't for her faithful husband Shining Armor, she would be grumpy too!

Still, she can't just sit by and watch her beloved aunts waste away in loneliness and anger! Maybe that old mirror hidden in her castle holds a solution...

Cover Art by TJPones

EDIT: Featured like 20 mins after posting (lol nice) on 6/3/19.

EDIT: #1 just a few hours after posting! Glad you all are liking it :3

Anon has been forced into Canterlot's throne room. Even worse, Princess Celestia is inside of it. Crying silently.

Welp, there's only one real solution here.

Boops.

Now's the time to hope this isn't a crime of any sort, and that he isn't sent to the sun anytime soon.

First publicized story- would definitely appreciate criticism.

And being completely honest- this was made in under an hour. A product of sudden inspiration.

Edit 5/17/19: Christ, featured less than an hour after it was posted and generally liked- i'm honoured. Glad you all enjoyed my silly little story!
As of 12/12/22, this still manages to appear on popular stories and featured occasionally when I post, which I cannot fathom-

Now featuring a Ko-fi for the generous, looking to help me out or the folks I want to support in my life.

Cadance didn't know what to expect when her formerly banished Aunt Luna returned from her thousand year banishment. But, she's quite entertained by the hilarity. Especially if it means a chance to play a little joke.

Edited by Habanc. Preread by The Albinocorn, Foals Errand, and Timaeus

Cover art was done by Silfoe and used with permission! In fact, this fic is a gift for her!

Now with Spanish translation by SPANIARD KIWI.

You've been in Equestria for about a month now, and have had the privilege of becoming friends with Princess Celestia, the land's kind and fair ruler.

Close friends.

Very close friends.

That's probably it though...right?

EDIT: Featured at #3 on 7/2! I'm glad you all enjoyed!
EDIT: #2 on 7/3! Wowza!
EDIT: (Same day) Now with an AUDIO READING by MultiDoomPie!

Rainbow Dash was just cruising through life, one cupcake at a time. However, after a freak encounter in the kitchens of Sugarcube Corner, the pegasus finds herself faced with something she's never encountered before: love.

However, this is not your average love story. For you see, the object of her affection isn't some handsome stallion with a windswept mane and gorgeous abs. No; her love is a sink.

Now, Rainbow must face the challenges that come with love, all while learning to deal with strange urges, teething children, and dresses.

This fic is also available in French and Italian! Thanks to Bro-Nie and FiMvisible, respectively, for their hard work.

A big thanks to Golden Vision and Pav Feira, my editors! This fic would be even worse without them!

Chrysalis kidnapped a dozen ponies, threatened Equestria, was betrayed by her own kind, and has now vowed vengeance on Starlight Glimmer before leaping from the ruins of her castle and flying off. She is definitely going to get away.

Absolutely.

Yep.

Reading by TheCaptainSand - Scarlett Blade

Translated into Spanish by ZodiacalComet

Sunset and Twilight stop to consider something serious. Is it really okay for a camp counselor to be hitting on one of the teen campers at an overnight camp?

Spike has been spending a lot of time with Flitter, a local pony in town who is (at best) an acquaintance of the Mane 6. Rarity sees this and launches straight into action, enlisting Twilight Sparkle's aid in getting to the bottom of Flitter's intentions with her dear Spikey-Wikey.

Teen Rating for some suggestive passages.

Beautiful Cover Art by the generous Blackflash, and vectored/edited by the splendiferous CaioCoia!

EDIT: Featured 9/21/16! Thanks so much!
EDIT: Hit 4k views 10/7/16- Most successful story so far. I'm glad people enjoyed it!

Nice clothes? Check. Bouquet? Check. Prettiest little nurse girlfriend of all time? Double check!

All that needs to happen now is for this big romantic surprise date plan to go off without a hitch. She'll be swept off her feet by dinner at a fancy restaurant, feel as special as she deserves to, and know that she is loved beyond a shadow of a doubt. It'll truly be a special night.
Well, assuming nothing goes wrong, but why would it?
No, of course not! Everything is definitely going to go perfectly according to plan.

Amazing art by Ezoisum, who you should go check out. Will take down if requested.