Chen Nianzhi's gaze shifted slightly, and he recognized the origin of the sword as well.
The Scarlet Abyss Ancient Sword was the peerless killing sword that the Six Tribulation Chaos Beast King had once wielded to slaughter in all directions within that Incomplete Immortal Domain.
Yet compared to back then, the Scarlet Abyss Ancient Sword now seemed to have mended some of its flaws, making it several degrees more powerful than before.
Most crucially, the sword was being wielded by a Seven Tribulation Ancient Immortal. Its might far surpassed its former glory, instantly transforming into streaks of Undying Sword Qi that pierced through Chaos and slashed down, driving everyone back step by step.
Chen Nianzhi had initially intended to use the Flying Immortal Zither to resist it, but he dismissed the thought in an instant, for at this moment, the White Rainbow Sword Immortal and Yin Celestial Son had attacked with all their strength.
The White Rainbow Sword Immortal unleashed towering Sword Intent that soared into the sky, manifesting the Hierarch-level divine ability, White Rainbow Heaven-Slaying Sword, to strike across the vast expanse. In the blink of an eye, he had exchanged several rounds with the Scarlet Abyss Ancient Sword and had somehow not been utterly defeated.
"Ten-limit mana."
Seeing this, Chen Nianzhi's gaze flickered slightly.
The White Rainbow Sword Immortal had actually cultivated ten-limit mana. Empowered by such mana, the might of his innate divine ability rose sharply, barely managing to hold back the Scarlet Abyss Ancient Sword.
This left Chen Nianzhi somewhat astonished. Since attaining the Dao, this was the first time he had witnessed the power of ten-limit mana through another person.
Back then, Chen Nianzhi had also sensed at least one ten-limit power from Eight Tribulation Ancient Immortals such as Zhuyin. However, since they had not