"Do it." Jason Sutton handed the small knife to Brian Sutton, then said, "This is to prevent high-level demons from sneaking into the valley. Some demons are born with extremely advanced transformation techniques—even top experts can hardly see through them. Therefore, only blood can be used to judge."

Brian Sutton suddenly understood, took the small knife, and gently made a cut on his index finger, letting the blood drip into the stone bowl.

"You two may go in. Remember, life and death are up to fate." After speaking, the two white-bearded old men waved their hands and closed their eyes, saying no more.

Inside the Hidden Valley, the cliffs rose sheer and tall. Between the two cliff faces, countless caves had been carved, densely packed. At the edges of the caves, one could faintly see figures sitting cross-legged, motionless.

"In the Hidden Valley, the stronger you are, the higher you reside. Three hundred meters is the dividing line—those below three hundred meters must not disturb the cultivation of those above. I came here once tens of thousands of years ago, and again several thousand years ago. But I have never seen any of the masters who live above three hundred meters. Some of them have been cultivating alone like this for hundreds of thousands of years, completely motionless."

Brian Sutton smirked a little, thinking, can't I just fly up and take a look? Jason Sutton looked at Brian Sutton with a smile, as if he could see through his thoughts, and said, "Try flying up to three hundred meters."

Hearing this, Brian Sutton sensed there was something strange above three hundred meters. He said nothing more, bent his knees slightly, and shot upward like an arrow. The higher he went, the greater the air resistance became. Above two hundred meters, his flying speed was almost the same as walking. He barely made it to about two hundred and fifty meters before he could go no further. It was as if the entire space above had turned solid, like a massive block of cold iron, preventing anyone from approaching.

Suddenly, the true energy in his body stalled, as if it was about to be exhausted. Helpless, Brian Sutton slowly descended to the ground.

"Well?"

"I could only get to about two hundred and fifty meters."

"Ten thousand years ago, I could only reach two hundred and eighty meters. Later, I could only go a meter or two further—any higher was impossible. The higher you go, the stronger the aura of those experts becomes. The aura they unintentionally emit gathers together and is almost like a real attack. The gap between our strength and theirs is too great; we simply can't enter the upper levels. Right now, everyone in this Hidden Valley is below three hundred meters. Those above three hundred meters haven't shown themselves for many years."

Brian Sutton looked up at the sky, feeling the dense spiritual energy and swirling currents of true energy in the upper layers, and mused, "Are they... all in secluded cultivation?"

"That's right."

"In this Hidden Valley, there is a spiritual array set up by a Supreme, gathering spiritual energy at a rate hundreds or thousands of times faster than self-cultivation. That's why many independent cultivators gather here to train. Of course, the most important point is..." Jason Sutton looked into Brian Sutton's eyes and said calmly, "This ancient world is nothing like the spatial plane we originally came from, where a technique could be mastered in just a few decades. My clan may not compare to the Celestial Bird people or those otherworldly demons, but our numbers are not small. Yet, along the way, how many people have you seen? None, right? That's the reason. In this world, truly powerful and miraculous techniques cannot be mastered in less than tens of thousands, hundreds of thousands, or even millions of years. The more powerful the technique, the longer it takes. The rarity of ancient humans is mainly because most are in secluded cultivation. I myself have cultivated for tens of thousands of years to achieve a little. But my nature can't endure endless years of training, so I came out for a walk. In this Hidden Valley, above three hundred meters, those should all be experts cultivating powerful techniques."

"So long!" Brian Sutton blurted out, recalling the Sword Body Great Art he obtained in the temple, but he had no idea how long it would take to master it—tens of thousands, hundreds of thousands, or even a million years? He already had a huge gap in years compared to everyone else. If it really took that long to master, then in those tens of thousands of years, if he encountered powerful demons or even hostile human factions, what would he do then?

Thinking of this, Brian Sutton's brows gradually furrowed. Although he understood that martial cultivation could not be rushed, everything he had seen so far—even the low-level demon beasts were not easy for him to handle—this harsh reality made him anxious.

"Let's go. When the boat gets to the pier-head, it will go straight with the current. Let's head inside first." Patting Brian Sutton on the shoulder, Jason Sutton lifted his head and strode into the thick mist. Brian Sutton snapped out of his thoughts and quickly followed behind Jason Sutton.

The further they went, the more spacious the interior of the Hidden Valley became, while the mist grew thinner and thinner. About a kilometer from the entrance, there was no mist at all.

At the base of a cliff on one side, by a dark cave, Jason Sutton stopped. Facing the deep, dark entrance, he cupped his hands and called out in a clear voice, "Junior Jason Sutton has come to pay respects to Senior Demon-Slayer."