Kai looked at the magic circle and took a deep breath, knowing the battle would be harder from now on. This magic circle felt familiar for him, making him think about the past. He gulped down, pointed his sword both at Ria as well as her magic circle, and murmured something almost soundlessly.

Soon after, he pretended to close his eyes to focus on his hearing. In reality, he was baiting her to make the first move.

"Sword Incarnation." Ria Ross smirked as she activated the magic circle on the ceiling. However, none of the swords actually flew toward Kai. Instead, she was the one who charged at him, swinging her sword.

Kai opened his eyes with a trace of surprise. Nonetheless, he blocked Ria's sword with the sword on his right hand. The Vibration Sword cut through her sword in almost an instant. It was at this time, he finally heard three noises coming from above. One of them came from right above him while the other two flew around and attacked him from the side.

"!!!" Kai swung his other sword to the left, splitting the sword into two. On the other hand, He used his right sword to destroy the sword on his right.

As soon as the swords clashed, he realized something wasn't right. The swords that flew toward him from the side continuously flew toward his head. And because it had been split into half, it would attack him from the front and back of his head before crashing into each other.

He had seen something like this in his match against Isabelle. The sword would ricochet toward his head if they crashed, and the sword that came from above him was there to make sure the shattered pieces would go toward him.

In fact, she thought about this possibility the moment Kai used his Vibration Sword. By having the swords bounced, she would be able to kill him. A surprise suddenly appeared on her face when she saw Kai ducking. Ria instantly remembered the battle between Kai and Isabelle and cursed her.

The moment Kai ducked down, the only thing he could see was a kick from his teacher. His two hands couldn't react to this kick, but if he received this kick, which was aiming at his stomach, he might receive more damage than he expected. He thought about using his foot, but it was sealed by ducking down.

Noticing how hopeless he was, he gritted his teeth and took the kick head-on.

"Bam!"

"Gah!" He spat blood before the kick blew him away and crashed into the wall.

"Boom!" It created a small crater on the wall before a few rubbles fell to the ground.

Ria didn't give Kai a chance and sent another three swords at him. Kai didn't let out a groan even once and endured his pain before coming out of the wall and rolling to the side. After this, Ria stopped her attack because Kai had regained his bearing again.

"Hehe… That match against Isabelle allowed you to avoid my attack." Ria smirked.

"I admit that." Kai nodded. "If I didn't encounter those ricocheting bullets, your sword would pierce my head before I knew it."

"Hehe… It's good then. As long as you are able to improve yourself on every occasion, I am satisfied." Ria smiled.

"Still…" Kai paused for a moment, straightened his back, and bowed to her. "Thank you for your guidance."

"As expected, you notice it." Ria Ross smiled before explaining. "I can say that there is one good news and one bad news for your Vibration Sword. I will say the good news first. It is powerful close combat magic… I have no doubt it will reach one of the top strongest close combat magic.

"However, there is bad news as well. I don't know if the intelligence beast will find this or not, but I'm sure humans will know about this weakness as long as they are experienced enough." She paused for a moment before continuing, "And the bad news is-"

Before finishing her words, Kai already answered her. "It's too powerful."

"Exactly." Ria smiled and nodded.

Outside the room, Tasha couldn't help but exclaim, "Eh? The good news is powerful and bad news is too powerful... Is she joking around?"

"Ssshh…" Michelle put her index finger on her mouth, gesturing Tasha to shut up before turning back to the screen.

Ria explained. "Just like before, I use a weak metal for that sword. I'm sure you won't even feel a restriction and cut those swords like butter. It could be exploited in a few ways and I use one of them. It might fail to kill you earlier, but you should note it down in your head."

"Yes. I will be careful."

"Well, that Vibration Sword is really useful, especially against magical beasts. Assuming you can cut down your enemy in one single swing, even I want such a technique." She shrugged.

"Haha… Teacher is already powerful. If you have this ability, I don't have a chance to win against you." Kai smiled.

"Oh. You sound like you can still win against me?" Ria smirked while narrowing her eyes.

"Of course." Kai pulled back one of his swords before pointing his palm toward Ria. A magic circle appeared in front of his palm.

Ria furrowed her eyebrows, not feeling anything about this. She thought this was his shield before realizing something off. The battle between Kai and Isabelle flashed in her mind, specifically the scene after Isabelle flew to the sky.

At that time, Kai used his magic circle mysteriously before Isabelle focused on him again. This was certainly strange because there was no sound or whatsoever.

"What is-" Ria suddenly felt her eyes aching before going blurry. It felt like the eyes were shaking… no, vibrating. "You!"

Kai smiled. "As I said earlier, I am planning to win against you, Teacher."

"Tch!" Ria gritted her teeth while sending another wave of swords from above.

Unfortunately, Kai already focused on defending to buy time. Ria's speed was indeed fast, but it was still within his range of power.

She jumped to the side, but Kai kept pointing the magic circle at her, continuously shaking her eyes. The eyes felt like it wanted to jump off the sockets, so she knew it was the time to end it.

Ria Ross sent another three swords toward Kai. The latter simply smiled as he slashed the three swords. This time, Kai had deactivated his Vibration Sword, so he only blew the swords away.

Knowing Kai was only buying time, Ria blinked her eyes continuously, enduring the pain on her eyes. "This is really a good technique. You are attacking my eyes by attacking with a sound wave with the same frequency as my eyes. If I'm not wrong, it's 19 Hz."

"!!!" He knew that Ria had figured his technique out.

"Why don't you attack my heart? I am sure that I will die earlier than this." Ria Ross said.

"Teacher, do you know how seismic surveys work?" Kai asked.

"I know. This is still in the scope of your study. Wait-!" She suddenly came to a realization. "I see. So you are telling, a portion of your sound wave will be reflected by my skin, then some of it will be refracted. Summing it up, only a portion of the original Sound Wave will come to my heart.

"On the other hand, the eyes are much easier to attack because it's too exposed. No one would suddenly close their eyes just because of this since they are relying on their eyes to see their opponent.

"And the moment they realize, they could lighten the process, it's already too late for them." Ria Ross laughed. "You must be saying; it's faster to cut someone down than waiting for your attack to kill them."

"Teacher has gotten the point." Kai smiled as he looked Ria Ross closing her eyes. However, he knew it was already too late as blood began flowing out of her eyes like tears. At this point, he could say that he had succeeded in blinding Ria Ross.

"Still, this is really dangerous because you can make someone blind without them noticing. If the government knew this…" Ria wasn't flustered even though she just lost her vision. Instead, she acted like nothing happened.

"I know. I might be targeted. That's why I am not using it unless necessary or I know it's okay." Kai finally leaped toward her after destroying her eyes. He slashed at her neck to kill her.

Unfortunately, Ria Ross got the better of him. She grabbed Kai's wrist and redirected it somewhere before slashing his right hand. "If you think I can't fight without my eyes, you are still a naive boy. Although I am not like you, I can still use my ears and instinct to sense your movement."

"!!!" Kai gritted his teeth despite going through so much pain by having his hand cut.

"Even so, not screaming right now means you have gotten accustomed to the pain. This is another proof that my training is successful." Ria Ross smirked.

On Kai's forehead, veins bulge out, hating her comment. Even so, he still didn't make a sound. Seeing how his hand and sword flew, he abandoned the magic circle on his left hand and grabbed the sword before slashing at her neck once again.

Ria twitched her eyebrows, barely sensing the attack. Luckily, she still had time to react. She tilted her body down, but Kai still managed to take her right hand. His sword continued toward Ria's neck.

At the same time, he also sent a kick at her head, hoping to crack her head with his extraordinary strength in case she still managed to escape from his sword.

Seeing how the situation turned hopeless, Ria smiled.