"Alright, after this past month, your foundation is quite solid. I think it's time to teach you something new," Lin Luo said as he stood on the lawn outside the house in the early morning, addressing the two girls opposite him.

Throughout this month, Youxiang and Xiaozhi had been relentlessly pursuing monotonous endurance training, mental conditioning, physical conditioning, and limit-breaking exercises. Apart from the single day they spent outing, they were required to cultivate for no less than sixteen hours every day. Even while resting or sleeping, they diligently practiced the breathing and spiritual nourishment techniques Lin Luo had taught them.

It could be said that they strove ceaselessly for greater strength.

Although this month had been intensely arduous for them, their progress was equally immense. Initially, they could only sustain a full-power offensive for half an hour before needing a break, but now they could maintain it for nearly two hours, marking a roughly fourfold increase in physical stamina and endurance.

Furthermore, their control over power had seen substantial advancement. In the past, while their attacks appeared fierce, a significant portion of their energy was wasted. Now, every strike could be delivered with precision in terms of lines and surfaces, minimizing energy dissipation to almost negligible levels.

Even with Lin Luo strictly compressing their rest periods to a mere two minutes, they could rapidly recover the necessary stamina in such a short timeframe. This was the tangible benefit of their powerful spiritual energy and the optimal reward reaped from repeatedly pushing past their limits!

No one is born overwhelmingly powerful; Yakumo Yukari and Kazami Yuuka are no exception. Their future strength is entirely predicated upon the hard work and dedication they invest now.

Effort and diligence always yield returns; this is not a hollow platitude. At the very least, Youxiang and Xiaozhi have proven it. By steadily accumulating all their exertion and sacrifice, the gap that once seemed a chasm between them and the Thirteen Protectors has narrowed considerably, making the latter no longer seem so unattainable.

While a one-on-one victory remained impossible, if the two of them joined forces against a single Protector, the outcome would be a fifty-fifty proposition.

Such a phenomenal leap in progress was not only unbelievable to them but also left the Thirteen Protectors utterly dumbfounded. Such weak, insignificant yokai, growing in just one month to a level where they could contend with them—it was nothing short of a miracle!

On one hand, they marveled at the girls' rapid growth; on the other, they showered Lin Luo with effusive praise, citing his masterful guidance, calling him an unprecedented and unparalleled mentor. "If I had a master like you when I was young, I wouldn't be one of the Thirteen Protectors now; I'd be a Lord..." Their flattery had two aims: primarily, to curry favor for better meals, and secondarily, they were genuinely impressed. After all, even a Lord-level yokai might not achieve such results in instruction.

However, Lin Luo knew his role was merely that of a guide. The lion's share of credit for Xiaozhi and Youxiang's progress belonged not to him, but to the girls themselves. If calculated strictly by metrics, he deserved only thirty percent of the credit, the Thirteen Protectors perhaps ten percent, leaving a full sixty percent to Xiaozhi and Youxiang’s own effort and perseverance. They inherently possessed significant potential; with appropriate direction, soaring to greatness was inevitable!

Given this, Lin Luo decided that the foundational training phase was complete, and it was time to introduce them to truly formidable skills.

"Really?!" Hearing this, Xiaozhi and Youxiang instantly displayed excitement. Despite the undeniable progress, they hadn't exactly disliked the previous monotonous drills, but the prospect of learning more potent abilities was undeniably thrilling. They couldn't help but become animated.

"Of course," Lin Luo said with a smile, nodding before becoming serious. "But just because my foundational training stops doesn't mean yours does. Even after learning more advanced techniques, you must continue daily training until you reach your limit. Only this way will your foundation become unshakeable, making all subsequent cultivation yield twice the result. Do you understand?"

"Yes, Master!" The two nodded firmly.

"Good. Then, let's discuss what exactly we should teach you now." Lin Luo gave a slight smile, and as he spoke, a book suddenly materialized in his hand.

"What is that?" Youxiang asked curiously.

"The Tome of Genesis," Lin Luo stated in just four words.

Indeed, this was the Tome of Genesis he had acquired in the world of his magic teacher. He had kept it on his person all this time, yet never saw a need to bring it out. Although the magic within was potent—all exemplary spells inherited from the ancient era of the magical world—having mastered Creation and Destruction, Lin Luo could effectively supersede these spells. He specialized in creation and annihilation; as long as his strength sufficed, he could achieve anything, rendering the study of other disciplines redundant. Consequently, the Tome of Genesis had remained dormant, almost entirely forgotten, so much so that even Lin Luo himself sometimes forgot he possessed such a powerful secret manual.

Now, however, the Tome of Genesis finally had an opportunity to demonstrate its worth once more.

"This is a Grimoire, recording hundreds of the most excellent spells. There are those concerning space, time, spirit... all manner of potent magic. Moreover, after continuous refinement by generations past, these are no longer mere spells but true embodiments of power!" Lin Luo explained to the two. Because the world the Creator once inhabited was an age of magic, any strange ability was termed magic. Thus, some spells within the Tome of Genesis did not require a mage to learn; anyone with the requisite aptitude could master them.

After Lin Luo’s modifications, the Tome of Genesis no longer contained cryptic runes but scripts universally understandable. Lin Luo explained the contents while allowing the two girls to peruse it themselves.

When had Youxiang and Xiaozhi ever seen so many spells? Flipping through dozens of pages left them dazzled. What shocked them most was the sheer power of these spells—powers they hadn't dared to imagine before. They studied and listened, utterly captivated, yearning to master every single one instantly.

At this point, Lin Luo interjected, "I advise you to learn only one. Grasping too many things at once leads to mediocrity; it is better to become supremely skilled in one thing than broadly proficient in many."

The two girls paused, startled. If anyone else had made such a statement, they likely wouldn't have been convinced; in their current era, possessing more abilities meant greater security for survival. But coming from Lin Luo, they knew they had to seriously consider his words.

Lin Luo nodded. "Yes. You are still too weak. To be frank, some spells in the Tome of Genesis cannot be learned with your current strength. Even learning just one will take a considerable amount of time to master completely. Learning too many will only hinder your progress."

"We understand, just one," the two concurred after a moment of thought, accepting Lin Luo's counsel readily. Xiaozhi believed her Master would never harm them and that his logic must be sound. As for Youxiang, she felt her own comprehension aptitude was already poor; if she struggled with one, mastering several was out of the question.

Seeing their quick agreement, Lin Luo nodded again. "Then, begin your selection now." As he spoke, he placed the Tome of Genesis before them and watched them quietly.

This immediately left Xiaozhi and Youxiang slightly flustered. The sheer number of powerful spells within the Tome of Genesis was overwhelming; how were they to choose? Seeing Lin Luo maintain an air of detachment, they realized this decision rested entirely on their own shoulders. With a sigh, they dutifully bent their heads over the pages, searching for a potent spell suited to them.

In truth, Lin Luo already had a specific spell in mind for Xiaozhi. Within the Tome of Genesis lay a spell uniquely suited to her—or perhaps, one that was inherently meant to be hers: the third-ranked spell among the Ancient Supreme Magics—the Power of Boundary! Currently, Xiaozhi could only manipulate the gap between dimensions, her potential for Boundary manipulation yet to manifest. But Lin Luo knew she would master it, as the future her was the Gap Yokai who controlled Boundaries.

However, Lin Luo decided not to choose for her. He wanted to gauge Xiaozhi's own discernment: whether she would overlook the immense compatibility of the Boundary Power to chase the even more formidable first and second-ranked spells, or if she would opt for a comparatively lower-tier spell for the sake of rapid mastery. Either choice would compel Lin Luo to re-evaluate his assessment of her. Similarly, it might mean extending his stay here. Only by selecting Boundary upon first sight would she prove worthy of the future Yakumo Yukari, and only then could he feel at ease.

The two girls immersed themselves in the selection process among hundreds of spells. Although they were a bit overwhelmed initially, they soon calmed down, becoming lost in their reading, utterly forgetting their surroundings.

Xiaozhi examined the pages meticulously. She found many spells appealing, but Lin Luo’s mandate forced her to choose only one, leaving her uncertain how to proceed... Page after page turned, yet she found herself unable to discard any option. Some excellent long-range or spiritual spells caught her eye, but learning only one meant sacrificing a portion of her inherent advantages; yet mastering them all was impossible... Just as Xiaozhi began to feel a headache coming on, her gaze suddenly locked.

A single spell leaped into her vision, capturing her attention completely.

With scarcely a moment of hesitation, Xiaozhi pointed at that spell and exclaimed excitedly, "This one! This is it! I want to learn this one!"

Lin Luo looked, and then he smiled.

It was indeed the Boundary Power.