Time looper in AOT

Back Side of the Orphanage

Thud!

"Attention!" Armin shouted.

"Geez, big bro Armin, relax! Big bro Eren already said it's a holiday today," Rae complained.

"Huh? Did he?" Armin scratched his head. "I guess I'll just give you extra homework then."

"Booo!" The kids all gave him a thumbs-down in protest.

Armin's duty was to teach the orphan children. At least, that's what everyone thought. In reality, he was teaching them things far beyond what anyone within the Walls could even comprehend.

Subjects like advanced mathematics, chemistry, physics, code language, biology, and many other disciplines—far beyond the basic education available—were part of their lessons. These were things Eren had taught him and was still teaching him.

"Ahh, so fascinating… Who could have known that everything is made up of atoms?" Armin sighed in amazement, sitting down to study while the others played.

After a while, he stood up and headed toward the secret lab Eren had built for his experiments.

"Hey, big bro Armin! Look at this drawing! How is it?" A nine-year-old boy named Jake ran up to him excitedly, holding up a piece of paper.

Jake was one of the orphans they had saved, and he had a talent for drawing.

Armin smiled as he looked at the picture. However, upon closer inspection, he was stunned. But then, he smiled again.

"It's really good! But what scenery is this?" he asked. The drawing depicted Eren, Mikasa, and Armin standing with their backs turned, looking at a vast body of something that resembled a clear sky.

"Oh! Big bro Eren said this is the sea! I just tried to imagine what he described and drew it," Jake said proudly.

Armin stared at the drawing with longing.

'The sea, huh? Someday… Someday, we'll see it for real. Not just that, but also burning water, lands made of ice, and snowy plains of sand…'

"Is it good? I showed it to big sis Mikasa, and she said it was really good!" Jake said expectantly.

"Of course it's good! After all, you're our chief designer," Armin praised. This was a title Eren had given him.

"Well then, can you take it to big bro Eren? It's time for physical training, but he seems busy," Jake said, handing over the drawing before running off.

Armin glanced in the distance, where many orphans were doing various exercises under Mikasa's strict supervision.

"Ahh, I feel bad for them… Hope Mikasa goes easy on them today," he muttered, watching several of them on the verge of collapse.

Armin resumed walking until he reached a wooden house. He opened the door and stepped inside.

Click. Creak!

"Huh? Armin, what's up?" Eren, hearing the door open, turned around.

The room was filled with various objects—metal pieces in different shapes, glass tubes filled with strange liquids, stacks of papers, and books scattered everywhere.

"Nothing much, just checking on you. Have you found out what that black liquid is?" Armin asked as he walked in, eyeing what Eren was working on.

It had been several days since their discovery, and Eren had been obsessively researching it day and night.

"You're just in time, Armin! Today, you're going to witness the turning point of humanity," Eren said smugly.

Armin raised an eyebrow as he watched Eren work. Using a makeshift distillation setup—built from scavenged metal pots, glass tubing, and a coiled copper cooling system—Eren was carefully heating the crude oil.

They watched as different substances evaporated and condensed into separate containers.

The heavier sludge settled at the bottom—worthless for now. But then, a thinner, golden liquid collected in another container. Eren carefully dipped a cloth in it and struck a spark. A faint blue flame flickered to life.

"Success," Eren grinned. "We have fuel."

Armin watched in amazement.

"Now, we just need to convert fuel into motion," Eren continued.

He scavenged old metal parts from abandoned machinery and built a crude boiler. Filling it with water, he set up a burner using the refined oil and waited.

As the heat rose, steam pressure built up inside the chamber. The pistons trembled—then moved.

Armin held his breath.

Electricity requires motion. Eren took an old iron wheel he had crafted, wrapping thin copper wires around a salvaged core, forming a simple generator. He connected it to the spinning steam-powered turbine.

The wheel turned. The coil moved through the magnetic field.

A spark jumped between two metal contacts.

A tiny bulb flickered to life.

Inside the wooden house, Eren and Armin stared at the glow in awe.

"Wow… It's glowing… like the sun," Armin whispered in shock.

Eren felt a rush of excitement. He had built electricity from scratch. This was the power of a scientific mind. With enough time and resources, he could recreate the modern era.

"This—this is what I call electricity!" Eren declared with pride.

"Electricity, huh…" Armin muttered.

"With this, we can change everything!" Eren continued. "We can build heaters so people won't freeze in winter, light up the night, develop long-distance communication—and so much more!"

Armin felt overwhelmed by the possibilities. But then, his expression darkened as he remembered something painful.

Eren immediately noticed. "What's wrong, Armin?"

"Eren… you know what happened to my parents, right?" Armin said quietly.

Eren's face hardened. "Yes."

"You know why they were killed…" Armin trailed off.

Eren clenched his fists as realization hit him.

"Don't worry, Armin. Right now, we're just learning. We won't expose anything until we understand exactly what's going on," Eren assured him, his voice firm.

Armin's parents had secretly developed a hot air balloon, hoping to escape the oppressive rule of the king. However, the Military Police discovered their plan and executed them.

Eren had come to believe that the royals wanted to suppress knowledge and prevent people from discovering the truth. If people could fly, they could see beyond the Walls. So many Scouts have died searching what's outside but they still tried to bury this invention. The king clearly doesn't seem to like people knowing what's outside.

So they erased everything—including Armin's parents.

To be continued…

-------

Hi guys I just want to say give me some powerstones and comment to motivate me more.

Also I think it's time to be little serious afterall it's Time loop story haha.