After retreating to the cliff, Kai checked his surroundings to confirm that it was safe. After all, he didn't want another ambush to happen. It was enough for the ape to ambush them.
"Sorry, that was my fault. I shouldn't have let my guard down. I thought it was gone."
"Leave that for later, the problem is what we should do about the centipede."
"Yes," Ayaka nodded. "But, is that centipede really a B-rank magical beast? It's even harder than the A-rank ape that we fought two weeks ago."
"Judging from its power, it should be a B-rank magical beast. But you've seen its movements. It can move its body like crazy, and it looks like the centipede can think of the best option to dodge or to attack us." Kai said.
"What? Do you mean..."
"Yes. The centipede seems to have gained intelligence," Kai nodded with a serious expression.
Ayaka gasped when she heard that. But she felt something was wrong. "But Teacher said that this world is only for training. And the difficulty won't be too hard since the purpose of this world is to make us familiar with magical beasts."
"That's also what I was thinking. But no matter what, we've met that centipede. I don't know if others have also met that centipede or not, but our goal is still the same.
"It's to kill magical beasts, and the centipede is one of them. However, we have a second option, which is to avoid the centipede. But I don't think the centipede will let us do that," Kai told her.
"Then, you want us to kill the centipede first?"
Kai nodded.
Ayaka was confused. "How can we do that?"
"Do you know about seismic activity in geophysics?" Kai asked.
Ayaka had never heard that term before. She shook her head in confusion.
"To put it simply, it's a method to know about the ground's condition. We'll send a sound wave to the ground, and the wave will be reflected by the rock formation inside the ground.
"Before civilization overturned, this method was popular for searching for petroleum inside the ground.
"We'll dig the ground for a little bit, and I want you to make an explosion inside that ground. It should be possible with your magic.
"The sound waves emitted by the explosion will then be reflected by the rock formation inside the ground. The result will be received by a geophone. You can say it's a tool to receive that."
"But we don't have that tool... wait, don't tell me..." Ayaka realized Kai's plan.
"Yeah. My ear will be the substitute for the geophone. I should be able to locate the centipede," Kai nodded. "This method is similar to using a radar. I've been thinking about this method for a while.
"I have the concept ready. But I haven't managed to succeed in doing it. You might already know this, but you should know that there's another reason why we have to have a scout in our party.
"We can just use something like radar, but the radio waves emitted from the radar will be picked up by the magical beasts. Before civilization overturned, it might be good to use a radar as the animals around might not notice it or be hostile to it.
"But after they evolved into magical beasts, their ferocity and senses evolved to an unprecedented level. Eventually, people realized that radars can be noticed by magical beasts.
"That's why they stopped using it... But I'm a sound magician. I've been researching this magic. And by using my ears as the receiver, I should be able to recreate something like radar without magical beasts noticing it."
Kai explained his plan because he trusted her. He knew that Ayaka wasn't the type to blabber something like this. And even if she tells others about this, they wouldn't be able to use it as Kai relied on his special ears when he made this incomplete magic.
"Well, it's still only a concept, so we're going back to a simpler but effective one, which is the concept of seismic in geophysics. We'll locate the centipede with it," Kai said.
"But what will we do if the centipede is out of our reach?"
"We can ignore it for a while, but if the centipede is within our reach, we'll attack. After all, you also don't want to kill other magical beasts while constantly worrying about it, right?"
Ayaka agreed with him on that.
"That's why we're going to kill the centipede."
"But even if we manage to locate it, how do we kill it? My fire is ineffective against it."
Kai looked down when she said that, pondering over something.
Not long after, Kai answered, "I'll be the vanguard, and you'll be the attacker."
"What?" Ayaka was shocked beyond belief. Kai just told her that after she told him that her fire was ineffective.
Kai raised his hand and made a stop sign. "Let me explain it first.
"You can use that new skill, right?"
Ayaka didn't know why he asked that, but she nodded.
"We'll use that as our main offensive," Kai said.
She contemplated why Kai said that. After a few seconds, she finally realized what Kai wanted from her new skill.
"You want me to use the new magic to boost my spear so it can penetrate the centipede's... head..."
Kai nodded with a smile. "Yeah, you're right. Do you think it's possible with your new skill? it is hard, you know."
"We won't know until we try," Ayaka said.
"Sure, but we should get down from the cliff first," Kai said while looking to the ground. The cliff height was around sixty meters tall or so, so Kai absolutely didn't want to descend with his magic alone.
"Sure, let me give you a ride," Ayaka nodded and stretched her hand. But she suddenly realized that they were going to hold hands.
She then remembered that they were also holding hands when they were fleeing from the centipede. She didn't have any weird thoughts back then because of the situation.
But she finally realized this, and her face became red.
Kai only looked at her in confusion, as he didn't know what was inside her head and why she suddenly blushed.
But she had offered her help, so she gritted her teeth and grabbed Kai's hand. After all, unlike Kai, who was unique, she was only a high-school girl.
"Fire Wings!" She tried her best to ignore it as she immediately dragged Kai to the ground below.
When he landed, he was wondering if he should kill the magical beasts nearby. After several considerations, he decided not to. They were going to move as soon as he located the centipede, and it wouldn't take too long.
Thankfully, Kai needed to ponder a few things, and it gave her time to calm down. After Ayaka calmed down her flushed heart, she asked, "We're going to dig the ground here?"
"Yes. We don't need a big hole. One or two meters deep should be enough," Kai said.
"All right," Ayaka nodded.
They already knew what tools to use to dig the ground. Obviously, it was their weapons.
Ayaka used her spear to dig the soil while Kai used his swords. As expected of weapons powered by magic, they could dig the ground easily. With just a minute, they got the hole they needed.
"After we locate the centipede, we'll immediately move, since this place might be swarmed by magical beasts."
Ayaka nodded her head.
Kai then retreated for about ten meters from the hole. Actually, he wanted to move a bit further, but they might be too far to regroup.
Kai then placed his ears on the ground. He looked at Ayaka and gave an 'OK' sign to her.
Ayaka nodded.
"Scarlet Explosion!"
"Boom!" The explosion was heard from the small hole.
"Roar! Roar!" The magical beasts nearby were roaring. Ayaka was starting to tense up as she looked at Kai.
After Ayaka used her skill, Kai could immediately picture the rock formation inside the ground. But he waited a little longer as the one he heard was only the ground around him.
The centipede wasn't around him. He continued to wait as the sound waves kept coming back to him in succession. And with the centipede being that big, Kai could notice the disturbance because of its body.
After around two seconds, he finally picked up the centipede's location.
Kai immediately rose from the ground and ran toward Ayaka.
"We're going to fly east. The centipede is around a hundred meters toward the east," Kai shouted.
"Fire Wings!" Ayaka immediately activated her Fire Wings after she heard that. Thinking about holding hands with Kai again made her blush, but she shook her head since they had no time to think about that.
Kai grabbed her hand again, and they started to fly. There was another reason why Kai wanted to fly to the spot. It was because he didn't hear any sound from the sky.
In other words, there were no magical beasts that would come their way.
And soon, they arrived at the spot that Kai located.
"Use your explosion in that spot!" Kai said while pointing at the ground.
Ayaka nodded. She made a magic circle while diving down to put Kai down to the ground.
"Scarlet Explosion!"
"Boom!"
"Fly up!" After the explosion, Kai immediately ordered her to fly up as he would become the bait for this centipede.
And right after the explosion, the centipede finally crawled out of the ground and showed its mighty figure.
Kai only smiled, "Let's start the third round, shall we?"