The sensation of his muscles growing and enlarging along with the other changes in his body was truly mysterious.

Combining the use of the Berserker Physique's harsh practice and high consumption of both nutrition and energy with the freshness of the Sun Soldier's Breathing technique was miraculous.

The discomfort and the intense ache in his muscles after being subjected to extreme wear and tear in the workout were washed away the moment the breathing technique allowed him to enter a state of calm. The energy lingering in the air around him flooded his body. A single breath was all it took to open his pores and allow the energy in the room to enter his body from all directions.

His body reacted drastically to the energy at first, rejecting it for a few seconds, until it realized that the energy was stimulating the recuperation of his body.

In the next few minutes, he recuperated much faster with more energy inside him. The energy influx was still spreading through every cell in his body, but the fresh energy around him was more invigorating.

His War Rune couldn't absorb the fresh energy in the atmosphere of the Origin Expanse because he was not practicing a special technique that allowed such a phenomenon, but that was no problem.

After all, his body required the fresh and vibrant energy of the surroundings to recuperate faster and stimulate his body. That way, he could change the way he breathed fundamentally much faster!

Michael was not sure how much time had passed but he felt refreshed once he stopped practicing the Sun Soldier's Breathing technique.

'Did I sleep?' He wondered when he noticed that he was not tired at all. It was almost as if he had been in a deep sleep while sitting cross-legged for eight hours, or more.

Usually, he felt a little bit tired after he woke up, and it would take an hour or two until his body and mind were fully awake, but that was not the case right now.

He opened his eyes after practicing the Sun Soldier's Breathing technique and he felt refreshed and was wide awake immediately.

His mind was clear, and he didn't feel sore when he got up from the ground either.

"...amazing"

Michael threw a few punches in the air, and went back to the ground to do a few push-ups before he got back up again. His expression was one of utter disbelief.

'Did the changes in my body already occur? I feel much stronger than expected, and my breathing feels more regulated and even.'

He had a hard time explaining how he felt right now. It was weird and something one had to experience in order to understand properly.

Michael threw a glance at the back of his hand to look at the refinement degree of his War Rune. Afterward, he sensed the remaining energy influx inside his body.

A third of the energy influx had been used up in a day. That was more than he anticipated his War Rune to absorb in half a day.

It was morning already, and his subjects were already bustling like usual, getting ready for the day's work.

Michael had a lot to do, whether it was to study the materials he received for the aptitude assessment or commanding his subjects to distribute more tasks. There was also the GPS treasure map.

However, instead of beginning to work, Michael decided to test himself again. He started with a few sets of push-ups, sit-ups, and other exercises in his room.

Once he was done with that, he left the room and went for a jog. Michael tested his acceleration, his top speed, and how long he could run at top speed without feeling tired out.

The results of his tests wouldn't be as accurate as they would be during the aptitude assessment, but that was not Michael's concern right now.

He was more intrigued about the changes in his body and how much he had improved.

His Tier-0 War Rune was not yet refined to the Peak stage, but his physique felt much stronger than the day before. He was close to the Peak stage, but it was not as if his body would have improved that much from the strengthening his War Rune provided overnight.

He had learned in school that the War Rune was a generator of power that had to be upgraded with the influx of energy. Due to the upgrades, the resultant power generated from the War Rune would constantly increase.

Such a comparison was simple, and it made sense. After all, the power circulating through the human body increased the further the War Rune was refined.

However, there was one point Michael hadn't been taught. It was something he realized only now.

No matter how much power the generator generated, the generator would be useless if it was put in a frail machine that broke the moment the generator unleashed all energy or a machine that was rusty. The generator wouldn't be able to use its power in the most efficient way and circulate it efficiently.

'Doesn't that mean, every Lord and Adventurer should be practicing body refinement techniques to keep their body up to date with their War Rune's refinement?'

Was that common sense, or did the school not teach him that intentionally? Michael was not too sure about that anymore.

However, he could tell that it was necessary to keep refining his body if he wanted to use the full potential of his War Rune's high refinement.

It would be a waste of time and effort to rashly advance his War Rune to the 1st Tier if his body was not able to handle the power it unleashed.

Fortunately, he had still some time left to find out more about the importance of body refinement, and the correlation between the War Rune's enhancements and the strengthening of the body through workouts.

As such, four days passed in the blink of an eye.

Michael continued to practice the combo of the Berserker Physique with the Sun Soldier's Breathing technique. And by consuming a large amount of Black Bear Meat to keep up with the high utilization of energy, Michael could vividly feel and see the changes that occurred in his body.

It was shocking.

After three days of hard work, he thought that he reached a threshold. Michael was certain that the improvements in his physique would slow down after the third day of his tests, and that he would have much more difficulty determining the extent of growth in his strength. However, he was proven wrong the next day.

On the fourth day, his War Rune consumed the remaining energy influx in his body. The Tierless War Rune's refinement degree reached the Peak stage.

The moment his War Rune reached the Peak of Tier-0, his body and mind were strengthened. Practicing the Berserker Physique technique afterward allowed him to sense drastic changes inside his body once again.

Did that mean he refined his body once again after his War Rune had been 'upgraded' to the Peak of Tier-0, or was it just the unrefined enhancement the War Rune provided that was refined through the Berserker Physique technique?

Michael was not too sure about that anymore