Genjutsu worked by interfering with the opponent's five senses, and the vast majority required visual contact to function. Close your eyes, and theoretically, most genjutsu stopped working.
"I see!" Might Guy exclaimed, as if a new path to defeating genjutsu-types had just opened up before him.
"You idiot, how do you fight with your eyes closed?!" Obito shot back. "Can't see your opponent's movements—that's just asking to die!" He was savoring the rare opportunity to feel superior to another dead-last. Moments like these didn't come often.
If Kurenai had known Hagoromo better, she wouldn't have let herself get emotional. She'd have realized that provoking people was basically his superpower.
"Fine, stick to your strategy. Don't come crying when you lose!" She bit out the words, and without waiting to see if he was ready, snapped two shuriken at him.
Genjutsu-type didn't mean genjutsu-only. She could throw things just fine.
Hagoromo's eyebrow twitched. Then he opened his eyes. Straight for the chest with both of them. Noted.
Still—shuriken as a direct frontal attack rarely worked against anyone competent enough to be worth fighting.
He pulled a kunai and deflected both with unhurried precision.
Clang. Clang.
They clattered to the ground.
"Thought you were fighting with your eyes closed?" Kurenai called out.
Instructors generally left mid-fight banter alone. Psychological warfare was a legitimate tactic.
Hagoromo was genuinely capable of getting inside someone's head. That just wasn't why he was talking. The honest reason was simpler: he liked running his mouth.
"Hm? Didn't I explain?" He put on the face of someone earnestly seeking clarification, tone thoroughly innocent. "Eyes closed was for your genjutsu. Did you use genjutsu just now? Because I'm pretty sure what you just threw at me is what most people call... shuriken."
Hagoromo's terrible personality... The thought surfaced in the minds of all three people who actually knew him, in perfect unison.
Predictably, Kurenai—now certain she was being made fun of—jumped from annoyed to furious. Three more shuriken, immediately.
Hagoromo deflected all three without breaking stride. "You can keep throwing those if you want. But if you're not going to use genjutsu, you've already lost. Shuriken is my department, not yours."
That was when Kurenai noticed it.
One shuriken had looped back around in a long wide arc, coming at her from outside her peripheral vision.
"When did—?!"
She'd missed the throw entirely. No windup, no tell, no indication he'd done anything at all. How?
The arc was long enough that it had lost momentum by the time it reached her. She raised her kunai and deflected it cleanly.
Clang.
Hagoromo's attack had done nothing.
Kurenai was about to remark on how unimpressive that was, when a voice from the sidelines cut through with sudden urgency—
"Watch out—Shadow Shuriken!!"
"What?!"
He hadn't thrown one. He'd thrown two. Both on the same sweeping arc toward Kurenai, one above the other—the second riding in the shadow of the first, skimming ten centimeters off the ground. And at one meter out it surged sharply upward, fast and hard, straight for her chest.
The warning had landed just in time. She threw herself sideways, barely.
The shuriken caught her sleeve and drew a shallow line across her forearm.
Without the warning, that strike would have ended the match. The kind of wound that sidelines someone for weeks.
"Sarutobi Asuma." Instructor Abe's voice dropped to something worse than a shout. "This is a one-on-one match. Outside interference is prohibited. If you open your mouth again, Yūhi Kurenai fails. Immediately." Not a flicker of deference toward the Hokage's son. That strike had been decisive, and Asuma's shout had turned it into a graze.
"Yes, sir." Asuma lowered his head. He knew. He'd seen Kurenai about to take a serious hit and the warning had come out before he could stop himself.
A match-ending technique, reduced to a scratch. That was on him.
Two shuriken. Perfectly synchronized trajectories across a wide arc. Shadow Shuriken technique—on standard shuriken, not the giant windmill variants. Under ten centimeters in diameter. The precision involved was frankly unreasonable.
Kurenai checked the wound. A graze. Not serious. What was serious was her right hand, still wrapped around her kunai—completely numb.
She put it together in about a second.
"You ran Lightning Release through the shuriken?!" The disbelief was genuine. Ninja who could use elemental jutsu with real proficiency were rare at the Academy level. More to the point—she was certain Hagoromo hadn't formed a single hand seal since the match started. So how?
Hagoromo shrugged. Said nothing.
"And with shuriken that small—how did you even do Shadow Shuriken?" She couldn't let it go.
This time he answered. His compulsive need to explain things had taken over and there was no stopping it now.
"Getting two small-mass objects to travel synchronized trajectories along a wide arc while preserving terminal acceleration isn't trivial. It involves magnetic force, magnetic declination, Coriolis effect corrections—I worked out a formula, though the real bottleneck in live application is the real-time calculation load on the user—"
"...Magnetic?" The explanation was actively worse than no explanation. Kurenai's head was starting to hurt.
"From a physics standpoint, magnetic and electric fields are the same phenomenon. Electricity and magnetism are inseparable—electricity is magnetism, magnetism is electricity. And Lightning Release, fundamentally, is just applied electricity."
Kurenai: "..."
Instructor Abe: "..."
Their classmates: "..."
Everyone was screaming internally. What did any of that mean? Why did I understand zero words of that?
Then the glancing around started. Someone nearby was nodding slowly. Did he actually get it?
Nobody wanted to be the one who looked stupid.
So, gradually, one by one, everyone started nodding.
"Obito—did you follow any of that?"
"Huh? Me? ...Of course I did. Want me to walk you through it?"
Guy wasn't the quickest, and he had his moments of operating on pure instinct. But he wasn't about to let anyone treat him like an idiot.
He gave Obito a long look.
"...No," he said. "I think I've got it."