Guan Tong left his home and went outside.
The streets were nearly empty. The devastating blow the first of the Apocalypse Rules had dealt to the population was obvious.
While others might not know the full extent, Guan Tong had glanced at his school's group chat. Out of a group of forty to fifty people, only about ten had surfaced to say they were still alive.
But despite such a heavy blow, society was somehow still functioning.
This was thanks to technological advancements. Guan Tong had discovered on his very first day after transmigrating that Celestial Water Star's technology was somewhat more advanced than his old home, Earth—ahead by about twenty to thirty years.
Here in North Star Country, for example, smart wearables, drone delivery, and basic autonomous driving were widespread. Industrial robotics were also extensively used in major factories.
But as for the future, it was hard to say.
The nations of the world had jointly declared they would not yield to the Apocalypse Rules and would protect civilization by vigorously developing high-end technology.
But if the Rules became increasingly difficult and the population continued to dwindle, technological progress would likely slow, stagnate, or even regress.
Guan Tong didn't dwell on it. He was a firm believer in living in the moment.
The immediate task was to pass the second Apocalypse Rule, and worry about the rest later.
He went to a nearby park and found many people already there, running.
Most were young, which wasn't surprising.
Although the government hadn't released the age demographics of the deceased, it was easy to guess that the middle-aged and elderly made up the majority.
Their stamina couldn't compare to that of the young; very few could endure 72 hours without sleep.
"Dammit! Not even five kilometers and I'm... How the hell am I supposed to run a full marathon?!"
A young man who looked like a college student, exhausted from his run, stopped not far from Guan Tong. He cursed under his breath, hands on his knees, gasping for air.
There were many others like him. In fact, many were in worse shape; they couldn't even run a single kilometer, let alone five.
Guan Tong knew he was about the same. The most he had ever run at one time was three to five kilometers.
He looked at the crowded track in the park, thought for a moment, and decided to leave. He went to a private self-service gym instead.
This type of gym was rare on Guan Tong's old home, Earth, but quite popular across the nations of Celestial Water Star.
After scanning a QR code for entry, you could access a small private room. The room contained a personal treadmill, a yoga mat, small dumbbells, and other equipment.
These small, self-service gym rooms were designed for people who preferred quiet or had social anxiety. Right now, it was perfect for his needs.
Guan Tong stood before the treadmill. 'The Rules don't specify that you can't run on a treadmill, so this should be fine.'
However, trying to cheat with it was definitely impossible. The Rules would certainly be extremely precise in tracking distance and time. No matter how one ran, the record would be accurate.
Guan Tong took his [Wordless Book] from the storage of his personal terminal.
He then mobilized his Psychic Power and infused it into the book. Immediately, the two characters for "Guan Tong" lifted off the page, manifesting as a Shadow.
Guan Tong had the Shadow stand on the treadmill, then he started the machine.
The belt began to move backward, and the Shadow, under Guan Tong's mental control, started to run.
After a short while, numbers appeared before Guan Tong's eyes.
Current Distance: 100 meters, Time Elapsed: 35 seconds.
'Is this the timer and distance provided by the Rules...?'
Guan Tong thought to himself. Only the Rules could accomplish something like this—projecting numbers and timers directly into a person's vision.
But the appearance of this record confirmed it for Guan Tong: the Shadow running counted the same as him running. It all went toward the total.
This gave him an idea.
For example, he could run on the treadmill while the Shadow ran in place beside him.
Since the Shadow had no physical body, it didn't matter how it ran.
This way, the distances covered by the "two" of them would stack, greatly reducing the time needed to complete the marathon.
'Most importantly, the Shadow isn't limited by "stamina." That means I can make it run at its top speed for the entire duration it exists.'
With a thought from Guan Tong, the Shadow instantly broke into a frantic sprint!
Its top speed was Guan Tong's own top speed, which he tested to be about 15 seconds per 100 meters.
Currently, at full Psychic Power, Guan Tong could make the Shadow exist for five minutes at most.
Having the Shadow run at a pace of 15 seconds per 100 meters for those five minutes would cover a total of... two kilometers.
'...That's way too little.'
A full marathon is 42 kilometers. If the Shadow could only run two of them, it would just be covering a fraction of the distance—hardly significant at all.
There were only two ways to solve this problem.
First, increase the Shadow's duration.
Second, increase the Shadow's speed.
Guan Tong felt the first option was unrealistic, because maintaining the Shadow's existence consumed Psychic Power.
He didn't know how to increase his Psychic Power limit at the moment, so five minutes was the maximum duration.
That left only the second option to focus on.
'Increase its speed, hmm...'
Guan Tong looked at the buttons on the treadmill, and his eyes suddenly lit up.
'If I crank the treadmill's speed to maximum, and then have the Shadow... no, that won't work. The Shadow isn't corporeal; it can't make contact with the treadmill belt.'
Guan Tong frowned in thought.
Just then, sunlight streamed in through the window, feeling warm on his skin.
'Warm... huh? Wait... the sun, sunlight... a shadow?'
Guan Tong suddenly looked down at the floor. The sunlight shining on him cast a shadow to his side.
'They're both shadows, so maybe...?'
Guan Tong manipulated the "Shadow" from the Wordless Book, making it touch the real shadow cast by the sun.
The moment they touched, they instantly merged into one, perfectly and seamlessly.
Moreover, Guan Tong could clearly feel that the shadow he could control had grown larger. This discovery filled him with delight.
'How did I never think of this before?'
Guan Tong found it incredible.
He had only just now realized that his summoned Shadow, upon contact with a shadow created by another light source, could absorb the latter into its range of control.
For instance, if he went outside now, found any tall building, and connected his Shadow to the building's shadow, he could control the entire, massive shadow of that building.
This gave Guan Tong an immediate sense of being "overpowered."
Although the shadow was non-corporeal and couldn't do much else, for dealing with the current second Apocalypse Rule, it was more than enough!
Guan Tong's eyes shone. He now knew exactly what to do.
He immediately drew the curtains to block out the light, then took out his phone, turned on the flashlight, and aimed it at the treadmill's belt.
Just like that, the shadow of the treadmill belt appeared.
Guan Tong then manipulated his Shadow to connect with the shadow of the belt.
Instantly, he could control the treadmill belt's shadow!
He then walked to the front of the treadmill, set its speed to maximum, and hit start!
"WHOOSH WHOOSH WHOOSH WHOOSH—!"
Driven by the motor, the belt spun at a frenzied pace. Along with it, the long shadow Guan Tong now controlled also began to "rotate" with extreme speed and over a great distance!
That's right. Guan Tong couldn't change the shadow's shape, but as long as the shadow he controlled was large enough, it didn't matter if it was humanoid or not. As long as it was "moving," it would count toward increasing his distance.
At the same speed, a humanoid shadow might cover half a meter with one step. But what about the "step" of a skyscraper's shadow? It could potentially cover several hundred meters!
Guan Tong looked again at the numbers appearing before his eyes, and a smile spread across his face.
Current Distance: 347 meters, Time Elapsed: 4 seconds
At this average speed of 86 meters per second, he would only need less than 500 seconds to complete the full 42-kilometer marathon. It was simply unbeatable!