Yuta's head snapped up as the sound of footsteps reached his ears, and he was a split second away from summoning his cursed energy when a familiar voice called out, "Easy, doesn't look like you're in the position to be fighting anyone right now, let alone your teacher."
A wave of relief rippled through Yuta's body as he realized that no matter the outcome of the domain clash unfolding in front of him, Satoru would be able to handle it.
"So, Kiniro can use Domain Expansion," Satoru stated as he stopped beside Yuta and joined in staring at the large black sphere floating a foot off the ground.
"Did you not know before?" Yuta asked with a confused glance in Satoru's direction, "I thought that you would have been the one to teach him the technique."
Satoru smirked and crossed his arms, "Nope, when it comes to jujutsu sorcery, I doubt that Kiniro needs a teacher; I'd imagine that he's been able to expand his domain the moment he learned how to manipulate his cursed energy."
"But isn't Domain Expansion the pinnacle of jujutsu?" Yuta asked only for Satoru to wordlessly dip his head, "Like I said, he doesn't need a teacher, his intrinsic knowledge is off the charts, and his ability to reverse-engineer sorcery he's unfamiliar with is unrivaled."
For a moment, Yuta was silent before a thought crossed his mind, "Then why does he call you Sensei?"
"Hmmm, you know I've asked myself that question a few times. At first, I thought it was just him joking around and making fun of our dynamic, but now I think that Kiniro does truly believe that I've taught him something worthy of being addressed as such."
"Really?" Yuta asked as he glanced at the closed-off domain again and pictured the powers battling inside, "What could you have taught him that's not related to jujutsu or sorcery?"
"My best guess," Satoru muttered as he reached up and pulled off the bandages wrapped around his eyes, revealing their startling crystalline appearance, "Is that I gave him some perspective about what it means to see what others cannot."
"See what others cannot?"
"The Six Eyes allow me to perceive the flow of cursed energy in extreme detail as well as physical space in conjunction with my Limitless technique," Satoru explained, "I imagine that Kiniro's eyes allow him to do something similar, but instead of being able to perceive the physical world in its truth, he sees emotion and, more importantly the souls of those around him."
"It's strange, but now that you say it, he's the only one I've ever heard talk about souls before you," Yuta muttered as he realized the strange occurrence.
"For good reason," Satoru replied with a somewhat grim look, "Anything involving the soul can be considered a very complex and powerful use of jujutsu sorcery. In fact, one of the defining factors of a Sorcerer is how familiar they are with the shape of their soul."
Yuta frowned, "That doesn't make sense. How can you see your own soul? Is there a technique I need to learn?"
"Unless your innate technique allows you to interact with souls, then no. Becoming aware of your soul is a far more intrinsic process; it happens in sporadic bursts, forcing your perception of reality to transcend what's considered normal. In fact, you've recently experienced one such moment yourself, very recently."
For a moment, Yuta was at a loss, but by process of elimination, he quickly realized what Satoru was referring to, "I executed a black flash against Suguru…and afterward everything felt different."
"Summoning the sparks of black for the first time is perhaps one of the most defining moments of a sorcerer's progression," Satoru explained, "It's the first time that they truly feel their cursed energy and soul. The fact that you managed to create the phenomenon so early on speaks well of your potential. I don't think it will be long before you manage to manifest your domain as well."
"Is domain expansion another example of understanding the shape of your soul?" Yuta asked, his curiosity piqued.
Satoru grinned, "Of course, it is. Domain Expansion is considered the most supreme technique a sorcerer can master for a reason. It combines all three aspects of sorcery: the mind, body, and soul, reflected by the three components of a complete expansion: the innate domain, the innate technique, and a barrier to enclose space. If any of the three are missing, then it can only be considered a partial expansion at best."
"Well then, out of the three, which one is the hardest to master?"
Satoru paused at Yuta's question and pursed his lips in thought, "That's a tricky question to answer. I could say it depends on the person, but that doesn't really clarify anything. So, to start, let me say that if you're not born with an innate technique, then you're fresh out of luck. At most, you would be able to erect a modified barrier and change the landscape inside to mirror your innate domain, but expending that much cursed energy just for a change in scenery is a terrible choice tactically."
Yuta coughed once, interrupting Satoru before he could go off on a complete tangent.
"Hmm, right, right, moving on the innate domain doesn't really count as something that can be learned because everyone is born with one, even curses and non-sorcerers. However, innate domains are intrinsically linked to cursed techniques, meaning that if you're born with one, you'll have a far easier time visualizing what essentially boils down to a mental landscape that embodies the mindset of the individual."
"So then creating a barrier is the hardest part?" Yuta inferred, though his tone was doubtful, "But that can't be right; aren't barriers a foundational technique? I'm pretty sure that I can create a barrier if I had to."
Satoru sighed, "This is what I meant, but it's a tricky question; no one component of a domain expansion is particularly complex; it's the sum of the individual parts and fitting them together that prevents most sorcerers from achieving it. The nature of domain expansion requires a very specific kind of mindset and determination. Expanding your domain can be viewed as imposing your vision and truth on reality and claiming a portion of existence for yourself. It requires ego and determination. More than anything, domain expansion is a mastery of self rather than a skill check."
"So you're saying that Jujutsu is a journey of self-discovery?" Yuta asked in a somewhat critical tone as Satoru made it sound like fighting the manifestations of people's darkest fears and desires was just a by-product.
Satoru held up a finger, "Technically, everything is a journey of self-discovery, but what I'm trying to say is that Jujutsu is irrevocably tied to the connection between the individual and their surroundings. And in general, the more powerful the soul, the more influence they have over their surroundings."
"And that strength can manifest as cursed techniques?" Yuta summarized drawing a proud smile from Satoru, who reached up to tie the bandage back around his eyes , "Yes, I'm glad you understood; it seems that this fight has helped your growth immensely. You've even managed to figure out the truth of your relationship with Rika."
Yuta stiffened, and his hand reflexively moved towards the ring hanging off his necklace, "I was the one who cursed her soul and turned her into a monster. I thought she was the monster when the whole time I've been the one keeping her prisoner all this time."
"I doubt this makes a difference in your mind, but you can't blame yourself. There are worse things to curse someone with than love," Satoru replied softly, before his head picked up and he stared at the Domain Barrier just as a sharp crack rang through the air.
A second later, the barrier collapsed, shattering like glass and raining to the ground to reveal Kiniro standing in front of Suguru, who was forced to stand upright by the chains tightly binding his every limb.
For a brief second, Yuta thought that Kiniro had managed to capture the curse user, until he stepped aside and revealed the massive hole where Suguru's stomach should be.
Looking up from the grisly sight, Yuta glanced at Suguru's face, only to focus on the eyes when he noticed that they were only hollow sockets with scorch marks on the surrounding flesh.
The silence was broken by footsteps as Satoru walked over, his face unreadable, though it was the quietest Yuta had ever seen his teacher.
"Why are his eyes like that?" Satoru asked as he stopped in front of Suguru's body.
"My maximum technique views the eyes as windows to the soul, if there's enough separation between the soul and its sense of self, it can forcefully sever the connection between the soul and its vessel which just so happened to be his body." Kiniro informed as the chains binding Suguru's body slowly unwound themselves and vanished up his sleeves, "It's not a painful death, if that makes you feel any better."
Satoru caught Suguru's body as it slumped forward, no longer held upright, "Was that the complete truth?"
"Complete truth no only partial…I'd imagine it's quite agonizing if you were fully conscious, but for my maximum technique to take effect, you have to be in a state where the definition of pain is up to personal interpretation," Kiniro admitted, "But I will say I underestimated him."
Satoru glanced at Kiniro, who paused for a second before continuing, "I told him that your soul would be able to endure my domain for longer…Now I know that's not the case. In terms of quality…his soul surpassed yours…Suguru Geto was stronger than you."