Over a month had passed.
"Hah!"
Satoru threw a punch at Rutosa's face. Her fist was wrapped in a bubble-like film of cursed energy. The strike that would normally be halted by Limitless instead grazed Rutosa's cheek.
"Domain Amplification? That's real progress."
Rutosa praised her without hesitation.
During this time, Satoru had been training in the Four Major Principles alongside Rutosa's five John Bodyguards.
Her progress in the Four Major Principles was astonishing. Even though she started a full year later than the bodyguards, she had already far surpassed them in just a few weeks.
Even without relying on Limitless, she could easily defeat all five bodyguards using only her basic cursed energy control.
Now she could even touch the edge of Domain Expansion and deploy a little bit of Domain Amplification.
"Hmm. But you still haven't grasped Reverse Cursed Technique?"
"Hah…" Satoru exhaled heavily. "Multiplying negative energy with negative energy to create positive energy… It's easier said than done. I haven't felt anything this whole month…"
Satoru felt a twinge of disappointment. She knew all the theory behind Reverse Cursed Technique—Rutosa had even compared it to nuclear fusion—but she still couldn't pull it off.
So instead, she had honed her skills in the Four Major Principles to grown stronger during this time.
During the Gojo clan annihilation, she had killed the Grade 1 sorcerer by leveraging Limitless's untouchable nature and Blue's Short-Range Instantaneous Movement, which let her attack the enemy like a dump truck with Blue's attractive force to manipulate the terrain at will to remove enemy's field advantageous.
With her near-limitless cursed energy thanks to the Six Eyes, she had worn the Grade 1 down to death in exchange for her own exhaustion.
But that was where it ended.
Her development of the innate technique Limitless had halted here. Without Reverse Cursed Technique, she couldn't access Red's repulsive force or the secret technique born from fusing Blue and Red.
Even after more than a month of training in the Four Major Principles, that fundamental limit remained unchanged.
"Well, it can't be helped."
Rutosa said calmly.
"Sorcerers who can use either Domain Expansion or Reverse Cursed Technique are already rare. Those who can use both are even rarer."
"Since you still can't use Reverse Cursed Technique, just don't rely on it. I'll teach you another way to apply Limitless."
"Huh?"
Satoru exclaimed in disbelief.
"(Another way to use Limitless?)"
In her knowledge, there were no other applications. Even with the accumulated experience and trials of previous Limitless + Six Eyes users, they had only developed Blue, Red, and Hollow Purple.
Beyond that… nothing.
Though she didn't want to admit it, even Satoru herself had come to believe Limitless was limited to those three.
Still, that alone made it superior to almost every technique in history.
Most innate techniques had only one core use. A few might have two, three, or four extensions, but that was extremely rare—Kamo's Blood Manipulation had the most extensions, with Limitless coming in second. Even the monstrous Ten Shadows Technique, which could stand on equal footing with Limitless + Six Eyes, had only one primary application in her knowledge: summoning shikigami.
She didn't know much more about Ten Shadows anyway; she hadn't been exposed much to its details during her training, and after the clan's destruction, the Gojo clan's records on it had vanished.
That's why Rutosa's claim felt so strange—there couldn't possibly be more to Limitless. Otherwise, elders and Gojo BMW would have mentioned it to her.
"What's the essence of Limitless? It's bringing the concept of 'infinity' into reality."
Rutosa didn't wait for her to answer.
"However, Limitless users usually apply infinity to the space around themselves."
"You already know Neutral Limitless: it takes finite space and divides it infinitely, manifesting Zeno's paradox in reality."
"Blue is infinite convergence toward a single point. Red is infinite divergence from a single point. Both involve infinity, but their core is still spatial manipulation—just like Neutral Limitless."
"Since it controls space, why not time? You should know from basic science that space and time are interconnected, right?"
Boom!
Rutosa's words hit her like thunder. She gasped as realization struck.
Space! Time! Infinity!
How had she missed something so simple?
Oh—right. She hadn't read science books before, and right now she didn't even know Einstein's theory of relativity.
"The method I'm going to teach you is hard to grasp and execute, but since you're already proficient in the Four Major Principles and still have no handle on Reverse Cursed Technique, now's the perfect time to try it."
"You know about gravity—a force that draws masses toward each other. Most people see it as one of the four fundamental forces or as gravitons. But a group believes it's merely an illusion, an effect caused by the curvature of spacetime."
"Mass bends the fabric of spacetime, and that curvature draws smaller masses toward larger ones. By understanding this, you can combine Neutral Limitless and Blue to create a gravity field."
"Try using Blue's attractive force over Infinity's infinite subdivision to warp the surrounding spacetime into a curved 'well' around your target. This is my original extension technique: Infinite Blue. It generates a spherical gravity field at the point you aim at."
Rutosa demonstrated. The air around him warped, a heavy pressure settling in. Dust particles fell straight down and sank into the ground. Notably, the technique activated instantaneously like Infinity and had Blue's long range.
"If you use Infinite Blue on yourself, you can create a gravity training ground anywhere, anytime. On an enemy, it catches them completely off guard."
"Moreover, the technique's potential doesn't end there. Since you're already bending spacetime to create gravity, why not bend it a little further for something even more incredible?"
Rutosa walked over and touched Satoru's shoulder, canceling the effect on her before activating Infinite Blue again.
"Maximum: Infinite Blue."
This time, something felt off—that's how Satoru perceived it.
She understood the gravity in the area should be crushing, heavy enough to sink everything—including the ceiling. But there was a strange sensation she couldn't quite place.
"Did your Six Eyes catch any change?"
Rutosa asked.
"It feels strange. Gravity seems stronger, but I don't understand why the effect isn't more intense than before."
"Hm. Good observation."
Rutosa didn't tease her with riddles. He pulled a coin from his pocket and tossed it into the air.
In Satoru's stunned gaze, the coin fell… very slowly. So slowly that a normal person could run to the bathroom and back before it hit the ground.
"T-this is… time deceleration…?"
"More precisely, time dilation. Maximum: Infinite Blue imposes time dilation on everything around the user. The range and strength depend on your cursed energy output. During dilation, your own body moves at normal speed while everything else slows down."
Rutosa explained, then flicked the still-falling coin.
"Your enemy would perceive you moving at lightning speed—even without Blue's Short-Range Instantaneous Movement—and the force scales proportionally."
Thud!
The flicked coin split in two; both halves flew and embedded deep into the wall.
Satoru, watching through her Six Eyes, knew Rutosa's flick had barely more force than a baby's—yet the coin's fate proved it had struck with far greater power.
"It's incredibly useful in both combat and rescue. You can exploit the time dilation to evacuate civilians or eliminate enemies before they can react or harm anyone."