Composite Illusion, Passed.

Several wooden shackles suddenly appeared in Uchiha Kō's world, their positions quite delicate, pressing against his muscles, making it impossible for him to exert force; any exertion caused pain throughout his body.

Damn it, is this the Genjutsu master? The two of them are not even on the same level! He is far inferior.

Then Uchiha Izuna appeared. "Little guy, you are now in my Genjutsu space. I will now teach you the Genjutsu of the Uchiha Clan."

As soon as he finished speaking, a message entered Uchiha Kō's mind: the Illusionary Demonic Illusion: Shackling Stakes Technique and the Illusionary Mirror Heaven and Earth Reversal.

"The reason I'm testing you is twofold: firstly, to see your magnanimity and courage; and secondly, to teach you some Genjutsu, because your mental strength is too weak. Although it's slightly higher than other ninjas, in my opinion, it's still trash."

"Even Senju Tobirama has stronger mental power than you. Do you want to learn from my elder brother and use brute force to break through all laws? But what if you encounter someone stronger than you? What if you encounter a strong person like Senju Hashirama?" Uchiha Izuna saw it clearly. If Uchiha Genjutsu strong, he wouldn't have been defeated in the end.

Uchiha Kō remained silent, absorbing the knowledge of the two Genjutsu.

"Ding, new Genjutsu detected, Mirror World Reversal, Demonic Illusion: Shackling Stakes Technique, now fully proficient for the host."

Uchiha Kō smiled slightly. "Grandpa, now it's a battle of offense and defense!" He looked up at Uchiha Izuna, silently chanting, "Magic Illusion: Mirror of Heaven and Earth Revolves!"

In an instant, the illusion shattered, and in reality, Uchiha Izuna was patting Uchiha Kō's head. His eyes flickered, and a smile appeared on his face. "Good lad, you learn very quickly!"

Then he fell into Genjutsu, and the same Demonic Illusion: Shackling Stakes Technique bound him. Uchiha Kō appeared before him with a smile, "Thank you for your teachings, Grandpa!"

"Thank you too soon." Uchiha Izuna sneered, then transformed into a shadow; the Demonic Illusion: Shackling Stakes Technique couldn't restrain him!

Uchiha Kō was startled, alert to what was behind him. He turned around and saw Uchiha Izuna descending from the sky with a katana, aiming to stab his Sharingan.

Uchiha Kō hurriedly raised his hand to block, but with a thud, the knife pierced his bone, and blood flowed freely.

"Grandson, you should know that although this is your Genjutsu, my mental strength is slightly higher than yours. Even if it is your Genjutsu, I can still use it for my own purposes." Uchiha Izuna stared intently at Uchiha Kō.

Uchiha Kō knew it was Genjutsu, but the pain felt way too damn real!

He attempted a grappling move to capture Uchiha Izuna, but Uchiha Izuna had vanished, and his attack missed. Immediately following, a kick came from behind.

"Weak, too weak, Uchiha Kō. Although you can rival my older brother in strength, you are far inferior in terms of mental strength and consciousness." Uchiha Izuna kicked Owl in the side chest.

Uchiha Kō was kicked away like a shrimp. He cursed inwardly, "Damn it, is there no way to fight back?"

"People often only realize their weaknesses when they are weak. Since you have weaknesses, think about how to turn them into your strengths!" Uchiha Izuna was in no hurry to take action, but simply looked at Uchiha Kō and gave him a hint.

In terms of Genjutsu and mental power, Uchiha Kō had no chance of defeating Izuna.

Uchiha Kō, panting heavily, looked at Izuna. Izuna, holding a katana, stood motionless, waiting for Uchiha Kō's move. In his opinion, his grandson didn't take Genjutsu and mental power seriously enough.

Perhaps his standards were too high. In this era, no one in the Ninja World, including the Kage of each village, possessed the same level of mental strength as Uchiha Kō Uchiha Clan. Even during the Warring States Period, apart from Uchiha, Uchiha Izuna, Senju Hashirama Uchiha Izuna and Senju Tobirama of the Senju Clan, no one else in the Senju Tobirama had stronger mental strength than Uchiha Kō.

It's just that Uchiha Izuna had too high expectations for his grandson, or rather, he believed that strict discipline would produce filial piety.

Uchiha Kō closed his eyes and sat cross-legged in meditation. Uchiha Izuna looked at his grandson with interest. Had he attained enlightenment? Was he meditating?

He planted the knife in the ground, leaned on the hilt, and waited to see how Uchiha Kō would perform.

"System," Uchiha Kō mentally called out.

The system advises the host not to call for help in situations like this. This is a good opportunity for practice; the host should think of a better strategy.

Uchiha Kō was cursing under his breath, but he still started thinking. This old man should have some ideas about the Uchiha Clan's Genjutsu, or rather, the Genjutsu of the Ninja World.

Furthermore, regarding mental strength, if Hashirama and Madara hadn't died, then his grandfather, Uchiha Izuna, would have been the strongest possessor of mental strength.

In other words, it would be a pipe dream for him to win against Uchiha Izuna in a single Genjutsu. First, Izuna has more experience than him, and second, Izuna's mental strength is higher than his. A single Genjutsu would be broken and reflected back if he used it.

If I want to defeat him, I must create my own Genjutsu. The casting of Genjutsu is inseparable from mental power, in other words, it is inseparable from imagination.

Many Genjutsu inventors created their illusions from their own imaginations, so he can too!

Immediately afterward, many ideas flashed through Uchiha Kō's mind. Finally, his eyes lit up, and he instantly opened them to look at Uchiha Izuna.

Izuna pulled the katana from the ground and looked at Uchiha Kō with interest. Just as he was about to greet him, his vision disappeared. He was somewhat disappointed; it was the Bringer-of-Darkness Technique.

He shook his head and was about to form a hand seal to break the seal when he discovered that he couldn't move his body!

Magical Demonic Illusion: Shackling Stakes Technique!

Uchiha Izuna was taken aback. When did Uchiha Kō use two different Genjutsu?

No, not two, it's one!

Uchiha Kō combined the Demonic Illusion: Shackling Stakes Technique and the Bringer-of-Darkness Technique, activating them simultaneously to form a new composite Ninjutsu. Even with his powerful mental strength, he couldn't break through the Genjutsu in a short time.

It would take at least a few seconds, but what can he do in those few seconds?

Uchiha Izuna sighed. When his vision returned and the Demonic Illusion: Shackling Stakes Technique on his body disappeared, he saw Uchiha Kō holding his katana to his neck.

Uchiha Izuna looked at Uchiha Kō with admiration and approval in his eyes, "You passed the first test, and you passed it beautifully."

Uchiha Kō chuckled, tossed aside his katana, and said, "Grandpa, shall we go out?"

"Hmm." Uchiha Izuna nodded, then his figure disappeared. Uchiha Kō dispelled the Genjutsu, and his consciousness returned to his original body.

"Are you done fighting? Izuna, you didn't hold back, did you?" Uchiha asked with a smile.

Uchiha Izuna shook his head. "No, big brother, my grandson is very smart. He was able to come up with a composite Genjutsu, which I didn't expect."

"I have truly lost this round," Uchiha Izuna sighed.

Uchiha's eyes lit up, and he pointed at Uchiha Kō, "Complex Genjutsu? You?"

"Ahem, what? Great Grandfather, can't it be me?" Uchiha Kō said irritably.