What Xu Fan had used was not Shisui's strongest genjutsu, Kotoamatsukami.
It was merely an ordinary genjutsu under the Three Tomoe.
As a genius of the Uchiha Clan, Shisui had mastered all kinds of genjutsu.
The instant those Anbu Ninja focused all their attention on him, Xu Fan directly used Shisui's eyes to drag them into a genjutsu.
However, if Kakashi had known this information beforehand, he might have been able to put up some resistance with Obito's eye.
Though it would only have been a slight degree of resistance.
When it came to genjutsu, Shisui's attainments surpassed even Itachi Uchiha's.
Furthermore, Kakashi had been entirely focused on how to counter Xu Fan's Wood Release, so everyone, including him, entered the world of genjutsu in an instant.
From the very beginning, they had never launched an attack. Nor had a large number of Anbu Ninja gathered at the training ground; at most, only a scattered few had been watching the fight.
But from their perspective, the battle was simply unbelievable.
Before Kakashi could even order everyone to spread out, his subordinates collapsed one after another, followed by him.
"What did that man do?"
"I don't know. I didn't see his movements at all..."
"See his movements... Did he really make a move? Why do I feel like he just stood there, and then Kakashi and the others fell one after another..."
The watching Anbu Ninja immediately began talking among themselves.
"Could it have been genjutsu?"
Suddenly, someone in the crowd cried out. In his view, if Xu Fan's speed had not been so fast that the naked eye could not track it, then the only explanation was genjutsu, one of a ninja's three great tactical arts.
However...
"When did he cast the genjutsu?"
"Isn't that a little too outrageous? Captain