A blinding light... the feeling of a cold, stone floor... a cold breeze flowing through the air...
These were the first things the human noticed upon waking up. Legends had always said that one with enough determination could cross the barrier, but the child had never believed it for themselves.
The human stood up and wiped the dust from their shirt. The walk up the stairs beyond the barrier had taken a lot out of them, and the human was eager to find something to get their strength back.
It had always been a dream of the child to leave the underground, they had heard rumors of the world that the monsters above lived in. Vast, open water... lights that cover the sky at night, and another light that shines during the morning... it seemed like paradise compared to the underground they had lived in their whole life.
The human looked up, seeing that they were in the midst of what looked like an ancient castle. Or whatever was left of it... The walls and ceilings were riddled with holes and cracks, and light seemed to pour from them like a river.
Walking forward, the human took in a breath. Even the air up here seemed better-
WHOOSH! A gust of wind blew at the child, and they looked to see that an ornate spear had been slammed into the ground in front of them.
"Who passes?" A voice demanded. The human had no response. A metal clanking was heard, and the human was able to make out an armoured figure.
"I repeat, who passes?" The figure tilted its head. "Wait... you're a..."
The armor-clad figure stepped into the light. It was tall, seven feet at least. The first thing that the human noticed was the head of the monster... it looked like a goat. Long, floppy ears, white hair, and a short snout. Where it was different from a goat was its human-like eyes, squinting at the child in curiosity. The human looked up, seeing two sharp horns on its head, making it look all the more imposing.
The monster's armor shined in the light, having a torn and faded cloth over the chest. It had some symbol on it... but the human couldn't make it out completely. Another equally dingy and faded cloth hung over its shoulders, and the back of its armor was covered by a cape made of the same material. "...you're a human..." the monster finished. He grabbed his spear and held it by his side. "...my apologies, I thought you were dangerous."
The human waited for the monster to say something else, but it just stood there awkwardly. "Are... you... Um..." the monster's eyes darted around nervously. "I... I'm sorry... I'm just not used to talking to humans. Or... anyone for that matter..."
A socially awkward guardian. What else did you expect? The human thought to itself.
The monster shook his head. "Let me start over. Greetings, I am the Sentinel of the Ruins. I keep guard over this place and protect its inhabitants." The monster's monotone voice rang throughout the ruins. He held out his hand. "Come with me, I will take you to-"
The monster was hit in the chest by... What were those, pellets?... and flew into the wall.
The human turned in the direction of where the pellets had come from and saw a small, golden flower.
"Howdy..." the flower croaked, which made the child jump in surprise. The flower tilted up, and it became apparent that it was wilted, six tattered petals surrounding the center, which had a toothy grin. The eyes were hidden by the top two petals, which hung forward over the eyes. "...I'm Flowey! Flowey the Flower!"
The human took a step back, this thing was creepy.
"Boy! You almost went with him, didn't you?" The flower nodded at the Sentinel, who was unconscious. "No, no, no... that would've been a mistake!" The human became encircled by the pellets from earlier.
"Say, you look pretty hungry..." Flowey said. "These... 'friendliness pellets'... are good for food as well as helping out best buddies!" The flower smiled. "Don't worry. You can trust me..."
The human decided to chance it. How dangerous could a stupid flower be anyway?
The pellets hit the child, weakening it severely.
"Hee hee hee..." Flowey cackled. "What an idiot!" The petals encircled the human once again. "Why don't I remind you why you humans should STAY underground?!" Flowey laughed as the petals flew closer, the human shut its eyes in fear... suddenly a ball of heat rushed past the human, hitting Flowey and knocking him into the darkness.
It was the Sentinel. He had regained consciousness, and was now picking up the human. "We need to get you out of here!" He said, racing further into the ruins. The human's vision started to darken... its heartbeat slowed...
NO... The human was not about to die... not now...
They felt themselves being set down on a remarkably comfortable bed, another monster similar to the Sentinel leaning over them. "Rest, my child..." a soft voice spoke. "...You will be better in the morning..."