This is Magic: Ereri Harry Potter AU! Fanfiction

Chapter 1: King's Cross Station

Hi! Welcome to this Ereri HP AU! I love AoT and Harry Potter, so I'll be super motivated to write this AU. If you notice any grammatical or spelling errors, please don't hesitate to let me know. I hope you enjoy this story!

        "All aboard! Train B leaves in 3 minutes!" A loud voice echoed through the huge brick train station. A young boy with chocolate brown hair and turquoise eyes flew through the crowds, pushing a large trolley with excitement. Two adults, male and female, rushed after him worriedly. 

        "Be careful, Eren! Don't leave your father and me behind!" the woman called. She wore a long, flowing white skirt and a light blue blouse. Her shiny black hair was tied haphazardly on the side of her head. Her husband was a tall, thin man with a small beard and glasses. Finally, they caught up to their son, who had stopped at a certain brick pillar. Eren stared at the wall, eyes sparkling with determination. HIs small hands gripped the handle of his trolley tightly.

        "I'm ready, mom. I want to learn magic already!" Eren proclaimed.

        "Ssssshhhhh!!" his mother scolded him, glancing around at the people bustling to their destinations. "What if the muggles heard you running your mouth about magic? You have to be more careful than that, Eren!" The brunet ducked his head shamefully and muttered a small "Sorry..." Right at that moment, an even smaller boy with long blonde hair and an oversized sweater ran towards the brick pillar. 

        "Bye, grandpa!" the boy yelled over his shoulder before disappearing through the wall. An elderly man standing a few feet away from Eren laughed and waved at his grandchild. Eren's eyes widened in wonder. 

        "Please, can I go now dad?" Eren asked quickly. Eren's father lifted the corners of his mouth slightly. It almost looked like a smile.

        "Alright, alright. You can go now. Be safe and polite on the train, okay?" his father lectured. The teal-eyed boy nodded his head furiously, wanting to be on the train already. 

        "And make sure you don't spend all of your money on candy!" his mother added. "You need it for emergencies!" 

        "Okay mom! Bye!!" Eren hugged his parents tightly before grabbing his trolley once more and sprinting towards the brick wall.  As he got closer and closer, his white cat meowed nervously and pawed at her cage. "It'll be alright, Echo!" Eren chirped excitedly.

When they reached the wall, instead of crashing into it, Eren and his trolley slid through it seamlessly. It was dark for a few seconds, and the brunet experienced an odd sensation like water flowing past him. It disappeared as quickly as it had come, and a bright light flooded Eren's surroundings. He squinted, trying to adjust to the sudden brightness. When his turquoise eyes had adjusted, the first thing they spotted was a wrought iron sign that read "Platform 9 & 3/4".

Eren was practically vibrating with anticipation. He pushed his trolley forwards, taking in all of the sights and smells. On one side of the platform, men and women were hugging their children, tears rolling down their faces. Older kids were together in groups, chatting animatedly about how their summer went. A few owls flew overhead, children running and calling their names desperately.

Eren smiled, glad that he had chosen Echo as a companion. The white feline was a great cat; she was uncharacteristically loyal and well-behaved. 

The brunet glanced to his left and gasped. On the tracks was a magnificent red and black train. It belched out black smoke and seemed to huff in eagerness. On the side of the head car was a beautiful insignia woven with gold. On either side of the insignia, it read "Hogwarts Railways".

Eren's eyes were fixed on the incredible machine before him. As he was walking, not paying attention to his surroundings, a raven-haired boy walked right into Eren's trolley. They crashed head on, Eren's bags scattering everywhere. Echo let out a loud protesting meow as her cage fell to the ground. 

        "O-oh my gosh! I'm so sorry!" Eren stuttered, rushing over to the other kid and helping him up. The other boy scowled at Eren, brushing dirt off of his white shirt and leather vest. 

        "Watch where you're going, brat," the raven growled. Eren flinched back, quickly stammering "Yes sir! Sorry!" before grabbing his bags and messily throwing them back onto his trolley. The other kid rolled his silver eyes.

        "It's Levi, not 'sir'," the boy commented. "I'm the same age as you, kid." Eren flinched in embarrasment and turned to bite back a retort, but before he could reply, the raven called Levi had disappeared in the crowd. The brunet stood there for a second, slightly dazed, before shaking his head and collecting the rest of this things. That was odd...

Eren quickly forgot about the mysterious kid as he walked through Platform 9 and 3/4. Train guards  announced the nearing dismissal of the train, and Eren started hurrying towards a luggage holder near the back of the train. He loaded his things quickly, making sure to give Echo to a handler, and then jumped into the closest entrance of the Hogwart's Express.

Eren practically ran through the narrow hallway of the train, looking into various compartments to find a suitable place. He passed by a few full rooms, getting more nervous the longer he looked, before he finally found an empty spot labeled "Compartment 104". The teal-eyed boy slid open the door and lifted his carry-on bag above the seat onto a shelf before sitting next to the window and getting comfortable.

Now that he was on the train, Eren knew that it would be a long ride before they reached the castle. He closed his eyes, praying for sleep, even though it was practically impossible with all of the adrenaline flowing through him. His thoughts drifted towards the silver-eyed boy. "Levi..." Eren thought. "That's an interesting name. Come to think of it, he didn't have any belongings with him."  WIth these thoughts in mind, Eren started to relax, and eventually drifted off into sleep.