After that new intake of magic, Kai began to improve. Instead of wasting his magic power away, he used it more efficiently. All it took was a few hours of practice to get a handle of it and Kai would be good to go.
Arba watched it happening with her own eyes, realizing that Kai truly had a good affinity with his magic.
"Thank you, Arba." Kai smiled while continuing to run in the air.
"It's my job." Arba waved her hand with a smile. "Though, I'm afraid you are going to need to take over if you have stabilized your posture and grown accustomed to your new magic."
"Yes." Kai nodded. "I think it will be fine."
Kai stepped forward to be in the front again while holding his swords.
"Still, I can't understand what kind of body you are trying to create… I mean, we are still running normally." Kai contemplated for a moment but couldn't find the answer. Running was running no matter the intensity, he thought.
"Yes. However, there are a few catches in this run." She smiled. "First, you are required to have a certain amount of speed."
"That's just a simple difference between jogging and sprinting, right?" Kai asked.
"Yes. However, the training takes you to another level because you are fighting air resistance. This friction will gradually kill your skin and replace it with another one. After all, your shape is not like a bird or anything that has evolved to be able to withstand the wind pressure and use it to their advantage."
"I see." Kai nodded in understanding. "I can understand the concept, but I don't know if it's good… I mean, from a medical perspective."
"You alone have surpassed humans." She shrugged. "Especially after getting the excess energy of this planet."
"Fair enough." Kai chuckled. "So, what's the second reason?"
"Second, it's to build up your physical body like how you are running to keep your body fit. Because you are running at a certain speed, it will increase the speed of your improvement as well. Of course, this can't be done by normal humans because they will be too exhausted to even do this kind of thing. Even I won't dare to do it unless I'm 15 years old."
"I guess the planet loves me so much." Kai smiled.
"Yes. In fact, have you ever got sick?"
"Ehm… other than my ears, nope. Ah, I see…" Kai finally understood the reason. He always followed his parents' words. They loved him and he loved them, so he thought it was normal that he was always healthy.
However, even the healthiest person in the world would get a cold or flu within twenty years of their life. Magic Particles didn't do much in this area.
"Yep. More or less, the reason is just to speed up your progress, so yeah…" She shrugged.
"Haha." Kai laughed before his expression turned serious when he heard a group of birds coming in their direction. "Hmm."
"Have you detected something that will catch us?" She asked.
"Yes. There are eleven birds coming." Kai nodded.
"In that case, I will let you fight again." Arba chuckled. "Besides, I believe the current you will be able to destroy them without feeling anything."
Kai glanced at her and shook his head helplessly. "What do you expect from me? Kill them from a distance?"
"That's up to you."
"…" Kai fell silent before thinking about another impossible thing. "Wait a minute… I feel like I can do something about this."
Kai looked at Arba's face for a moment.
Arba felt slightly awkward from his gaze and decided to tease him. "If my king desires my body, I shall serve you tonight."
"Nah, you can do it by becoming my meat shield in front of me right now." Kai chuckled. However, what Arba did when she ripped monsters apart without even touching them gave him inspiration.
This new magic was related to his Supersonic Sword, Sonokinetic Blade, and Oscillation Shield. His Supersonic Sword made his swords vibrate at a very high speed, sharpening the sword to the point it could almost cut everything.
However, this wasn't enough. Several S Rank Magical Beasts could block it with their body hardness alone and it wasn't like he could just stand a few minutes next to them to do it slowly, which enhanced its penetration effect.
To counter that one flaw, he gained a Sonokinetic Blade that contained both sharpness and power. Unfortunately, it also couldn't fulfill his truest desire. The Sound Wave would gradually become less powerful after traveling to the air. Just like how the sound was hard to hear from far away.
Hence, Kai took the concept of Oscillation Shield. Instead of going long, he returned to basic and made it small, just barely reaching out a few centimeters from his swords.
And Oscillation Shield did this the best because it formed some sort of kinetic energy from the oscillation around the shield surface to soften an attack coming at the shield.
Creating new magic was close to impossible, so he would try to reform his current magic to their most powerful form, like his Sound Blast.
He raised his sword and summoned a magic circle, covering his sword.
It was his Oscillation Shield, but he had enhanced it with his Sonokinetic Blade. It gave both the power contained in his Sonokinetic Blade, but the sound kept going back and forth an inch from the sword's blade.
This oscillating energy was powerful and acted as a chain saw. And without getting any contact, the bird shouldn't be able to stop his momentum or even slow him down unless its body was hard enough to create a form of resistance.
But with the concentrated power of his Sonokinetic Blade that allowed him to cut a cliff into two, it was close to impossible.
Seeing the power from the sword, Arba smiled and said, "I guess I don't need to be the meat shield."
"I was joking." Kai rolled his eyes. "You thought I was serious?"
"No, but I didn't lie either." Arba smirked.
Kai looked away and shook his head helplessly. "Anyway, the birds are in front of us and I'm ready to take them down."
"Sure thing." Arba slowed down her pace and hid behind Kai's body, preparing to take any action if something went wrong.
Meanwhile, Kai released this new improvised magic to its fullest potential.
The birds had brown colors and flew without any pattern or whatsoever like geese. They all were random and just flew together without any care.
Seeing such a thing, Kai quickly analyzed the perfect spot to hit them. He suddenly noticed a big gap that allowed him to go through after killing one particular bird.
"The size… Each bird is around one meter in height, and its wingspan is pretty good, so I guess this is a perfect time to test it. If this is a flop, my body will flip and I may lose my sword, but this is fine." Kai smirked. "If I don't dare to do this, I won't be strong enough to fight the enemy a year from now."
Kai's expression turned serious as he stepped on the air, increasing his pace for a moment.
Cry.
The birds released their cries and started changing their direction to swarm him. However, Kai used that chance to increase his speed to the limit, outrunning every bird except his target.
He then waved his sword downwards. The bird's body started getting distorted even before it made contact with the blade.
The distorted part was ripped apart like Arba did and continued until the blade split the bird in half.
Kai didn't feel resistance as though his sword didn't even touch the bird. In that instant, a smile appeared on his face.