Zuo Mu muttered to himself, no wonder Master told him and his senior brother not to seek revenge on the Sword Palace Assassins, but to go to Huaxia to learn martial arts, absorb the strengths of all, and then consider whether to seek revenge on the Sword Palace Assassins after comprehending them.

The Sword Palace Assassins were elusive and evil, but Xu Xiangbei was bold and skilled, with high martial arts prowess, and the righteous would conquer the wicked. He placed all his hope for vengeance on Xu Xiangbei.

After walking forward for a while, they reached the end of the corridor, where a damaged staircase led to the second floor. Looking back at the corridor they had come from, the first-floor corridor became unusually quiet.

Suddenly, elegant music drifted from the second floor, Zuo Mu cursed: "What tricks are they trying to play?"

Xu Xiangbei raised an eyebrow and sneered: "Whatever tricks they play, I’ll play along."

The two climbed the worn stairs to the second floor. Just stepping onto the second floor, Xiangbei and Zuo Mu were stunned.

The first floor was filled with rooms, while the second floor was a large platform, without rooms, only columns, and the space was broad, decorated with a refined elegance.

The carpet on the wide platform of the second floor was spotless, the integrated ceiling was shiny and tidy, wallpaper lined the walls, and lush green plants were placed on both sides.

In the center of the second floor, on a rosewood chair, the Sword Palace Assassin sat facing away from Xu Xiangbei and Zuo Mu, playing an elegant ancient zither.

The zither music was haunting and melodious, at the highs, it seemed like a torrent cascading down from a mountain, at the lows, it was like a spring murmuring, stirring the spirit.

When the rhythm was fast, it was like a thousand horses galloping, when leisurely, it was as if love and longing were entangled.

Xu Xiangbei laughed: "This old fellow even knows how to play the zither, but we can’t appreciate it, playing for us is no better than playing it to a cow, useless."

Zuo Mu took out a hexagonal dart from his hand: "Kid, do you think playing a tune for us will stop us from killing you? You’re dreaming."

Suddenly, the zither music changed from bright to gloomy, and the Sword Palace Assassin sneered with contempt at the corners of his mouth.

With a clang, the zither music seemed like ghostly wails and wolf howls, unsettling and agitating people’s minds. Xu Xiangbei thought to himself, is this the legendary Sound Killing?

Indeed, the Sword Palace Assassin’s fingers flew across the strings, the zither music became increasingly irritating and unbearable, even suffocating, like wanting to tear one’s throat apart.

Xu Xiangbei quickly took out his phone, played music, but the zither music was hundreds of times stronger than the phone’s music.

Xu Xiangbei realized that the second floor was a Sound Killing array.

The wallpaper on the walls, the suspended ceiling, the carpet on the floor, all were to maximize sound reflection, preventing absorption by the walls and floor.

Xu Xiangbei practiced the "Primordial Scripture" with deep composure, temporarily unaffected by the Sound Killing, but Zuo Mu wasn’t as fortunate, his nails clawed at his throat’s skin, blood seeping out. A little longer and he might sever his own throat.

Xu Xiangbei shook his hands, four Iron Gall collided with a clang, like a bolt from the blue, jolting Zuo Mu back to his senses and freeing him from the Sound Killing’s control.

Clang, clang, clang, the sound of the Iron Gall was melodious, like the tinkling of a spring, clearing away the anxiety and suffocation.

Suddenly, a dull sound was heard, one of the Sword Palace Assassin’s zither strings snapped under the interference of Xu Xiangbei’s dual Iron Gall, defeating his Sound Killing and causing his Inner Strength to fail to sustain the zither string.

He sneered: "Well, kid, you’ve got quite a few tricks. Let’s have a fair and open duel."

He reached behind him to draw out a gleaming long sword, flicked it with a sword sound, causing a dragon roar that was deafening in the spacious second floor.

Just from the sword’s sound, it was clear it was a fine sword.

Xu Xiangbei shook his hands, four Iron Balls flew out.

Clang, clang, clang, the clashing sound was incessant like popping beans, never ceasing.

Watching on the side, Zuo Mu was mesmerized, he thought Xu Xiangbei and the Sword Palace Assassin seemed like two light rings constantly colliding and intertwining, any mishap by either side could grind them to dust.

As the Sword Palace Assassin fought on, he became more and more alarmed. The swordsmanship he took pride in became clumsy before Xu Xiangbei, every strike easily resolved, just like last night in the small woods, the longer he fought, the less confident he became, the more restless he grew.

Suddenly, he swung a fierce sword, leaning towards the supporting stone pillar in the second floor’s center, a breeze blew by, and he vanished.

Xu Xiangbei’s Iron Ball struck the stone pillar, scattering stone fragments.

"Where is he, pulling off a vanishing act, frustrating me."

Zuo Mu chuckled wryly: "It’s a Ninja Technique Invisibility Technique, a method of using the environment to hide oneself. He has mastered it so well, it seems he’s reached the Chunin level."

Xu Xiangbei cursed: "Old man, stop hiding, come out for a fair duel, sometimes throwing darts, sometimes playing zither, and sometimes playing hide and seek. Aren’t you annoyed?"

Suddenly, a sword wind rose from behind, Xu Xiangbei swayed his hands, without turning around, two Iron Balls flew from left and right, striking the sword blade about to hit his head.

Swoosh, another breeze passed, the Sword Palace Assassin hid again in the stone pillar, vanishing without a trace.

Xu Xiangbei sneered: "You can’t beat me openly, so you resort to sneaky tricks. Evil never prevails over righteousness. Do you think these tricks can defeat me? You’re nothing but a big turtle."

A black light flashed from a stone pillar, the Sword Palace Assassin emerged from the stone pillar, still in his black clothing, thrusting a sword swiftly toward Xu Xiangbei’s back.

Xu Xiangbei’s dual balls flew out, directly striking the sword blade coming at him, simultaneously, two more Iron Balls flew stealthily upward, aiming directly at the stone pillar, blocking the Sword Palace Assassin’s retreat.

Thud, the Sword Palace Assassin attempted his trick again, but the two Iron Balls blocked his retreat, solidly smashing into his shoulder, causing him to grunt in pain.

Xu Xiangbei quickly spun around, the injured Sword Palace Assassin’s movements slowed, finally allowing Xu Xiangbei to uncover the secret of the stone pillar.

Some stone pillars were supporting pillars, solid concrete large pillars used to support the floor.

But some were intentionally placed by the Sword Palace Assassin, hollow in the middle, forming a flipboard that allowed him to enter, creating the illusion of invisibility.

And with his movements, he could deceive others, making it difficult to detect that he entered the stone pillar through the flipboard.

Having discovered the secret, Xu Xiangbei laughed aloud, the four Iron Balls smashed all those fake stone pillars into pieces. The fake stone pillars were connected to the third floor, and it was through the third floor that the Sword Palace Assassin shuttled back and forth among these fake stone pillars, playing a classic game with Xu Xiangbei.

Xu Xiangbei cursed: "Let’s go to the third floor, pulling off a magic vanishing act, so shameless."