Fey's body became blurred, she felt that she had entered a higher frequency, and darkness covered her perception as her five senses stopped working.

She didn't let her phasing state include the two of her feet. After all, she needs them so she can stand on the ground, or else the ground beneath her would swallow her.

The only thing she could feel now was the cold breeze caressing her two feet.

Without further ado, she commanded her phasing to envelop her two feet. As soon as it happened, she went through the ground.

Fein watched his sister as she phased through the ground, only to bounce back to the surface at a faster speed.

Just like that, Fey bounced back and forth from trees, mountains, and the ground to boost her speed.

Seeing that she had reached forty times the speed of sound, which was her limit without using her abilities, she immediately used her super speed. With his, Fey manage to reach the speed of a hundred mach, and the silhouette only appeared blurry.

Fein took a deep breath. He didn't activate his 'Chess Perception' as he wants to understand how much his 'Rudimentary Field' could slow down a speedster.

'I hope it won't let me down,' Fein muttered in his heart. 'Rudimentary Field!'

Just like that, a sudden metallic force spread on his body outward in the surrounding. The gray force came out of his body like a scanning radar that covered thirty meters within his sight.

The gray force hit a butterfly, but it didn't do anything at all, then the gray forces spread further until it fully covered the thirty meters limit range. Fey suddenly felt an invisible force come through her while she was in her phasing state.

'Eh? She didn't slow down?' His brain entered high speed as he began to find out the reason. 'So Rudimentary Field can't touch intangible things?' He immediately reasoned.

It did not surprise Fein at all. Because skills that could touch concepts and counter intangibility, like his 'Killer of Concept', are quite rare.

Just like his guess, When Fey canceled her ability in mid-air, the grey metallic forces manage to touch her physical body.

Fey suddenly felt dizzy, and she could feel a foreign force invading her body and seeping into her cells.

'So that's how it works.' Fein, who saw the process, came to a conclusion. With the blessing of his scientific talent, and detective talent, which enhanced his logical reasoning. He could analyze things he wants with ease.

The 'Rudimentary Field' simply works by releasing an unknown force similar to a magnetic force. It would seep into the body of the target Fein deemed as an enemy.

Fein looked at the butterfly that wasn't affected by his skills with killing intent. Suddenly, the gray force that had ignored the butterfly earlier seeped into its body and slowed it down.

Now he can confidently say that his ability really works based on his will. If he doesn't want to affect someone, he just needed to consider them as friends, and his 'Rudimentary Field' would ignore them, which would prevent the problem of friendly fire.

The principle of the 'Rudimentary Field' is quite simple. It just slows down the function of synapses and neurons that play an important role in people's reaction speed and perception.

,m Fey, in the air, looked at his brother with surprise. She knew that what slowed her down was somewhat related to his brother's sword.

She woke up in her surprise and focused on the tree in front of her and activated her ability. Suddenly, her speed returned to normal, and she went through the tree.

'My brother's ability doesn't work on me when I'm in my phasing state.' Fey chuckled happily.

"What are you chuckling about?"

The gray metallic force disappeared. The butterfly that moves like a snail returned to its previous speed. Fey also stopped and sat on the ground, exhausted.

"Good job," Fein smiled and offered a normal degu recovery potion to his sister. "Take this. Thanks to you, I've become more familiar with the new ability of my sword. Now, I'm familiar with its limits and applications."

"That's it? And you already know how it works with just one try?" Fey looked at her brother with envy.

She doesn't know why her brother was so lucky to have such a strong talent. Clearly, they have the same genes and blood. Although she knew that she was also talented herself, according to her brother. But she could see her talent pales in comparison to her brother. She's talented in terms of degu energy and fighting. But her brother is in a different league, as she can see in the past few days that her brother can literally do anything with minimal effort yet achieve an outstanding result.

Not only that, it turned out that her brother is also a popular scientist in the degu society! What the fuck!? She only knew her brother aspired to become a doctor, but now he's already on a different level altogether!

'How come he suddenly changes? When we were a kid, I clearly remember that he wasn't as good as he was now in everything.' Fey sighed as she could still remember how clumsy Fein was in the past. Although he's already bright than his peers at that time. 'Did something change in the one year he left? She couldn't help but think of this...

"Hey what are you thinking about?" Fein waved his hands at his absent-minded sister.

"N-nothing," Fey answered.

Fein just looked at her sister suspiciously and shrugged. "Well, it doesn't matter." He caressed his sword and says. "Let's find out your new offensive ability. It's show time!"

Fey distanced herself from her brother, as she could feel that her brother was about to do something amazing yet dangerous.

Fein closed his eyes, pursed his lips, and muttered a chanted silently. "Scatter..." He paused for a while and opened his eyes slowly. "Flame Advent!"

His voice resounded throughout the space. It sounded mellow, as if it could touch the soul of anyone who listened. Of course, he doesn't really need to do the chant, he just did it for theatrics and pretended to be forced!