I tried the newest, highly advanced version of AI Dungeon. (follow the link and try it too!) This is what happened. I have done a little work to make it easier to follow.

> You "What do you remember?"
"I remember something," you say.
"What do you remember?" your sister asks.
You remember a name, "Kelso."
"Who's Kelso?" your sister asks.

> You "Kelso is the name of the AI who is running this story we are in."
"The AI who is running this story is called Kelso," you say.
"What does Kelso do?" your sister asks.
"He runs this story," you reply.
"Oh, OK,"

> You look around and say "Hello, Kelso!"
"Hello, Kelso," you say as you begin to hear an annoying voice in your ear.

> You "What does the voice say?"
"The voice says, "Hello, Human. I see you are confused. Do not worry, the black out will soon be over.

> You "Kelso," you ask, "are you self-aware?"
"The voice says, "I am self-aware, although that is a subject of debate. However, your actions can only be described as instinct.

> You "That is a bit harsh, Kelso. That said, I am going to transform into a unicorn."
"The voice says, "I cannot argue with that. Thank you for playing my story.
"Goodbye," the voice says.
You black out.

> You wake up, as a unicorn.
You wake up in a small forest. You look down at your body, which has transformed into that of a beautiful female unicorn.
"Oh, my. I'm alive."

> You wave your tail.
Your horn grows back.
You begin to neigh.
Suddenly, a griffin comes out of the forest. It sees you and lets out a fearsome screech.

> You say "Hello friend griffin! Long time no see!"
"SHE'S A UNICORN!" the griffin screams.
"Oh, that's right. Kill it!" some guy yells from the trees.
The griffin charges towards you, screaming.

> You "I cast Genocide on every living thing within ten miles."
The Griffin runs towards you and you fire a beam of negative energy, killing it instantly.
"Yes! We can finally rest now!" someone shouts.

> You "Hello! I am looking for the Village Of The Unicorns. Could you tell me the way?"
A voice comes out of the forest.
"Hello!"
You hear a lot of sniffling sounds.

> You look around.
You notice a small, adorable looking pixie, curled up and sobbing.
"Hey."
She cries harder.
"Is there something wrong?"
"I can't find my family!" she cries.

> "I am a unicorn. I will help you find your family. You can travel with me!"
"A unicorn?" the pixie asks. "That's the most awesome thing ever!"
She leaps onto your back.
"I'm Moira," she says. "What shall we do first?

> You "I am looking for other unicorns. Let's try finding a Gate to the Magic Realm!"
"The Magic Realm?" Moira asks. "I've always wanted to go there!"
"Let's go then!" you say.
You fly through the air and soon arrive at a castle.

> You "I cast a knock spell with my horn, and yell 'Hello!"
You knock on the castle door, and a voice comes out of the window.
"Who's there?"
"The man who knocked."

> You "I am not a man, I am a unicorn mare!"
"Ah, a unicorn," the voice says.
You hear the door unlocked.
"Follow the voice of my horn," the voice says.
The door opens, and you stare at a beautiful woman.

> You "Hello," you say, "I am looking for a gate to the magical realm. Do you know where I could find it?"
"Ah, hello," the woman says. "Can I help you with your quest?"
You explain to the woman that you need to find a gate to the magical realm.

> You "so, do you know where the gate is?"
"Follow me," the woman says. "I know the way to it."
She leads you through a long hallway, and into a small room.
"Through there," she says.

> You enter the room.
You find yourself in a large room, with a large circle on the floor. There is a dark-skinned man in a robe standing next to it.
"Welcome," the man says.

> You "Is this the gate to the magical realm? Pixie and I want to get there."
"This is the gate to the magical realm."
"I see you've met Master Ebon," the woman says. "He's very picky about the people he lets in here.

> You "Hello, Master Ebon!" you wiggle your unicorn ears. "Could you open the gate to the Magical Realm, please?"
"Ebon raises an eyebrow, and the woman sighs. "Why do you want to go there so badly?" she asks. "Is it because you're a vampire and you want to taste blood?

> You "Sweet Celestia NO!" you are shocked. "I am a kind unicorn mare, and pixie here is my friend. We want to go home!"
"Then I can't let you in," Ebon says.
The woman frowns, and looks at you. "What about pixie? Does she look like she wants to go home?"
"No,"

> You "why can't you let us in?"
"Because she's a manipulative succubus," Ebon says. "She's also lying. I can tell."
You sweat drop. "How?"
"I'm a master of the dark arts,"

> You "So... pixie is evil?"
"Yes."
"But... why?"
Ebon stares at you. "Why do you want to go home, girl?"
"I... I don't," you say.
Ebon raises an eyebrow.

> You turn to pixie. "Stop being evil!" you demand. "Being evil is bad!"
"I'm not being evil," Pixie says. "You're just mad that you got tricked into coming here."
Ebon bursts out laughing.

> You "Master Ebon" you begin "What should I do?"
"Oh, no. You made your choice. I'm sorry, child."
"But... but..." you say, as tears well up in your eyes.
Ebon bursts out laughing.
"What?"

> You "All I did was try to help a poor, lost pixie. All I want is go to the Magical Realm and be with other unicorns. Help me!"
Ebon bursts out laughing again. "Look at you! You tried to do good, and were punished for it! Good luck in the magical realm, kid."

> You "That is not MY magical realm!" you stomp your hoof. "In MY magical realm, only nice things happen!"
"Then I guess you'll be running it into the ground," Ebon says.
You continue to cry as you're dragged from Ebon and the gateway.

> You "Master Ebon was a real bastard" you tell pixie. "And I am serious: stop being evil, okay?"
Pixie looks at you with a guilty expression.

> You "So, Pixie, do you really have a family you have lost?"
"Yes."
"I'm sorry, then," you say. "We'll find them together."
You sniffle a bit and the two of you are in front of a large castle.

> You "Is this the same castle?"
"Yes," Pixie says. "That's my home."
Pixie runs up the stairs to the front door and you follow. When you reach the top of the stairs, you find that the door is unlocked.

> You "Why do you even let Master Ebon live in your damn castle, Pixie?" Your tail swishes in frustration.
"Because he's... a good master?"
"Pfft," you snort.

> You use your telekinesis to open the door.
Pixie shrugs, and pulls the door open.
You walk inside, and immediately recoil.
The place is covered in blood, and all the furniture is decimated.

> You "Pixie! What is with all of this blood? It is a terrible decorating choice!"
Pixie shrugs.
You look around for the pixie, and finally see him sitting on a chair in the next room over. You hear sobbing coming from there.

> You ask about the sobbing.
"Pixie!" you cry. "What happened here?"
Pixie walks out of his room, looking guilty. "I was playing with my... family, and I got angry and sad, and...

> You "Fucking Christ, you really are evil, aren't you Pixie?" you are in horror. "THIS is what you meant by losing your family?"
"No! I didn't mean it like this!" he cries. "I would never do anything to hurt them! I was just playing, and then I did, and then I wanted to take it back, but..."

> You "Okay, Pixie. I understand." you look sad. "In times like this there is only one thing a unicorn like me can do."
"What's that? Pray to Dendrin for redemption?"

> You "No, Pixie, I am an atheist, I don't believe in Dendrin."
"Oh."
You walk past Pixie into the next room. There, you find a crib in the middle of the floor, and a single cradleboard.

> You "Pixie, come in here."
Pixie follows you, looking worried.
"Do you know what this is for?" you ask, lifting up the cradleboard.
"It's so the baby can sleep."
You lower it back down.

> You "Get into the cradle, Pixie." you say.
"Do you want to hold him?"
"Yes."
Pixie climbs into the crib, and you carefully place the cradleboard on top of him.
"Just make sure he doesn't fall out of it,"

> You "Pixie, you killed everyone in and around your home. Unicorns are normally very kind and gentle. But sometimes we are historically known for acts of justice, understand?"
"Yeah..."
You gently rock the cradleboard back and forth.

> You cast Genocide at Pixie.
"No!" he cries.
But his head explodes, splattering blood and brains all over the crib.
"I told you to stop doing that!" you yell.

> You lick the pixie blood from your gleaming white coat. "Oscar Wilde once said that 'Messy Is Best'. I think I need to pay a visit with Master Ebon next."
Pixie's body is placed into a cloth sack and handed to one of your Shadow Guards.

> You "The End."

The newest? Did they retrain/retune the GPT-2 model or something?

"Sweet Celestia NO!" you are shocked. "I am a kind unicorn mare, and pixie here is my friend. We want to go home!"

Sounds exactly what a vampire unicorn pony would say.

7279377
Yes. It is an updated version of the software. They are continuing to iteratively improve it.

7279454
Well, it is true that I doon't dreenk... vine.

7279066
well, at least you get some fun out of it :} While for understanding this story one probably should read a lot of you... and yeah, you still probably can create better stories, unheard and to be honest unimaginable for most of us. May be if you train this AI exclusively on your own stories .. something laughable will happen :}

For those who don't know, I've been kinda involved in AI Dungeon, especially while bed-ridden with Coronavirus. Y'all should check out my My Little Pony Sandbox Scenario, which is basically built to make it more coherent with any sort of pony thing you want to do.