Genjutsu: False Surroundings Technique is a basic C-rank illusion that overlays everything the target sees with a false image, making them believe they're looking at something completely different. It doesn't cause harm and is used purely to mislead the enemy's senses, so it's relatively easy to dispel. However, it can cover a wide area and affect multiple targets at once.
Genjutsu: Hell Viewing Technique is even more basic, a D-rank genjutsu. Everyone has fear in their hearts; as the saying goes, "The more you fear something, the more likely it is to appear." The Hell Viewing Technique manifests the target's deepest fears and makes them seem real to shake their spirit.
These two genjutsu—one C-rank, one D-rank—inspired Neiki to create his S-rank illusion: Abyss of Deception.
Neiki's innate talent at genjutsu is only slightly above average, but his Analyze ability lets him develop and master genjutsu at a speed even the genius Uchiha Itachi can't match.
Abyss of Deception combines the traits of those two basic genjutsu. Like them, it isn't directly lethal and is mainly supportive. Its sole purpose is to "decorate" the reality perceived by all living beings within its range.
That "decoration," however, is terrifying.
Before targeting the Hyuga main family, Neiki tested the technique on genjutsu specialists in Konoha, such as Uchiha Itachi and Yūhi Kurenai. When even they couldn't see through Abyss of Deception, Neiki knew he had succeeded.
Abyss of Deception alters everything seen, heard, and felt within its range to match the victim's expectations—much like Hell Viewing projects what the victim fears, Abyss of Deception projects what the victim subconsciously believes "should" be there.
Its strength lies in forcing objective reality to conform to the subject's inner logic, making it unbelievably hard to detect.
For example, it can make burying bodies look like planting trees, turn a corpse into a tree stump, or twist a desperate warning into a casual greeting.
Abyss of Deception hides reality, distorts truth, and swaps falsehood with fact. It retains all the advantages of False Surroundings and Hell Viewing: wide area, strong misdirection, high adaptability, and long duration. Aside from its high learning difficulty and extreme chakra cost, it is arguably the most powerful genjutsu an ordinary ninja without a genjutsu bloodline can hope to master.
For instance, Hikaru sits calmly in what he believes is the dignified clan hall, watching the authoritative Hiashi and the angry Neiki argue over something absurd:
"Red bean soup should be sweet!"
"Impossible, it should be salty!"
Hiashi looks agitated and seems about to stand up, but forces himself to sit back down and glances at Hikaru.
"Hikaru, what do you think should go in red bean soup?" he asks.
The timing feels odd, but since the clan head is asking, Hikaru still thinks seriously about it.
…
In reality, the room is filthy and long neglected. Hiashi and Neiki are facing off in a suffocating standoff.
The longer someone remains caught in Abyss of Deception, the more their ability to act on their own erodes. This is because living beings adapt to the "things should be this way" logic and slowly stop thinking critically.
At first, many branch-family servants like Koharu and Senma showed resistance. But as time passed, they grew duller, their minds fading, until they became as unthinking as trees—chopped up and buried.
Servants under its influence eventually wither and die, explaining the rapid decline of the clan head's mansion. Fortunately for Neiki, Abyss of Deception automatically "tidies up" the reality it covers, masking the rot with a pleasing illusion.
"I will not accept your terms… cough… you should kill your brother instead," Hiashi rasped, hair disheveled, rejecting Neiki's offer to trade the elders' lives for the younger generation, including Neji and Hinata.
"In appreciation of that attitude, I'll put Hinata's head on your desk tomorrow," Neiki replied without hesitation.
Abyss of Deception does have one major flaw: once someone sees through it, it will never work on them again. Hiashi, as clan head, had noticed something wrong during Neiki's transition from the second to the third stage of his Byakugan, at a time when Neiki was relatively weak. Suspicion is poison to illusions; once doubt takes root, the genjutsu collapses. Hiashi had broken free quickly back then, and if Neiki hadn't physically restrained him, Neiki himself might have been forced to flee Konoha in disgrace.
"Heh. You could chop off Hikaru's head first and I wouldn't even blink," Hiashi sneered, glancing at Hikaru.
"I think red bean soup should have soy sauce," Hikaru said, looking between them with a hopeful expression, waiting for praise.
Neiki glanced at him, nodded slightly, and drew his short blade.
Hiashi's expression tightened, his lips quivering.
Neiki remained calm, his tone mocking as he pronounced sentence:
"Red bean soup…
…should be salty.
"And someone who puts soy sauce in it is…"
—Dead.
The blade flashed.
"Wait—!" Hiashi's chains clattered as he roared, his messy hair whipping wildly.
"Too late."
The head flew.
Even in death, Hikaru's face still wore a gentle smile.
…
[Essence Collected: 7.1%]
…
Blood sprayed across the floor, red bubbles gurgling from the smooth cross-section of Hikaru's neck.
"Hikaru spilled paint. Clean it up," Neiki said.
Outside the study, Koharu—still scrubbing the floor—muttered, "Hikaru spilled paint. I'm cleaning it up."
Even with her eyes gouged out, she "saw" normally under Abyss of Deception; the illusion was projected directly into her mind, bypassing the need for physical sight.
Koharu quickly dragged Hikaru's body away.
The death of main family members was always troublesome. They were few, prominent, and every incident drew serious attention from both the Hyuga clan and Konoha's leadership. After all, only the main family truly represented the Hyuga clan's power.
But for Neiki, who planned to wipe out all remaining Hyuga at next week's clan meeting, any future trouble was meaningless.
Wiping a splash of blood from his face, Neiki said to Hiashi:
"Tomorrow, I'll reunite you with your daughter."
Hiashi stayed silent. The lower half of his face was lost in shadow, but the tremor in his shoulders betrayed the storm inside.
Neiki left.
Hiashi slowly raised his head, dazed. He wanted to shout, but no sound came out.
Neiki's cold promise weighed heavily on him.
His enemy was not just ruthless—he was inhuman.
…I'm sorry, daughter.
Hiashi closed his eyes. In his mind, he saw his shy, gentle child, crying for help, and the guilt tore at him.
But…
I can't.
Hiashi didn't truly believe Neiki would keep his promise and spare Hinata. Compared to her, the surviving elders were the Hyuga clan's last hope.
He repeated to himself over and over that this was for the sake of the clan's future—a burden only the clan head could bear.
"Oh, that's right. You have another daughter, Hanabi, don't you? No wonder you're so heartless. You like her more, right? I heard she's in the room next door, so I won't wait until tomorrow," Neiki's voice came again, cheerful and casual, drifting in through the window.
In the original timeline, Hiashi clearly favoured his younger daughter Hanabi, viewing her as the true heir, and had mostly given up on Hinata. That bias explained his coldness.
Believing he had figured out the reason for Hiashi's indifference, Neiki turned to leave.
"Wait…"
This time, unable to endure any longer, Hiashi finally broke.
"You… you devil… spare them, my daughters, and I'll tell you everything…"
He covered his face as tears poured down, suffocated by the guilt of betraying his clan.
"Heh."
"Sorry. Too late."
What?
Hiashi looked up, stunned, and saw Neiki watching him with a regretful expression.
"I keep my word. You chose to surrender too late. Well, you still have Hinata to carry on the bloodline, don't you?"
She had only decided to beg after Neiki said he was heading for Hanabi.
No such luck.
Neiki sneered and walked toward Hanabi's room, leaving Hiashi in utter despair, thrashing against his restraints.
When Neiki came back, the smell of fresh blood was even thicker.
Hiashi raged for a long time, swearing he would never speak, but when Neiki grew impatient and threatened to bring him another daughter's head tomorrow, the last of Hiashi's resistance collapsed.
After finally giving Neiki the information he wanted, Hiashi sagged in his chair, like a puppet with its strings cut.
In that moment, he chose to be a father rather than a clan head.
…
Moonlight filtered through the leaves, casting broken shadows across the ground.
Neiki glanced back and saw a huge, spectral Byakugan floating above the Hyuga clan head's mansion—the external mark of Abyss of Deception. To outsiders, it looked like nothing more than a decorative emblem or banner.
Abyss of Deception isn't a simple, one-on-one genjutsu but a spatial illusion. All perception within its radius is altered, but the outside world remains unchanged. That boundary is its obvious weakness.
Neiki's countermeasure was simple: maintain normal appearances outside the mansion.
As long as life outside looked ordinary, no one would suspect that the mansion itself had become a gaping maw waiting to swallow prey.
Thinking back on his "negotiation" with Hiashi, Neiki frowned. The technique's vulnerability to exposure was too dangerous. Its greatest strength was its undetectability—but once a survivor escaped and told others about it, its effectiveness would plummet.
Like an elephant in the room: once one person points it out, everyone can see it.
Improving this was a key direction for Abyss of Deception's future evolution.
By the time Neiki returned home, it was very late. The lights were still on. As he opened the door, the sleepy Neji, who had been waiting for his brother, jolted awake and stared, eyes wide.
"Brother, did you bring back a cat?" he asked, pointing at the small figure in Neiki's arms.
Neiki calmly handed the sleeping Hinata to him.
"You're sharing your room with her tonight."
What?
"W-wait, brother," Neji stammered, holding the tiny girl—at most two years old—looking completely lost.
What's going on?
His brother had been out for so long… and suddenly came back carrying a child?