One stormy night, Dān Fěi and her brother Dān Héng, protectors of the Tiān Xíng Jiàn, are pursued by the evil Xuán Guǐ Zōng clan. Although the clan's leader, Miè Tiān Hái, manages to kill Héng and retrieve the sword's hilt, Fěi manages to escape off a cliff. Meanwhile, a travelling swordsman named Shāng Bù Huàn comes across an umbrella covering a Buddha statue, where a peculiar man informs him that taking the umbrella will require him to do a good favor in return. As Bù Huàn returns on his journey, he encounters Fěi as she escapes from Xuán Guǐ Zōng members, prompting him to step in to protect her. After bringing Fěi back to the man he met earlier, Bù Huàn is confronted by the Xuán Guǐ Zōng's Cán Xiōng, who attacks Bù Huàn after the mysterious man sprays him with smoke making him believe he is actually Fěi. After Bù Huàn defeats him in battle, Xiōng severs his own head and sends it to Tiān Hái, who identifies the mysterious man as Lüè Fēng Qiè Chén.

Fěi explains to Bù Huàn and the peculiar man, who calls himself Guǐ Niǎo, that the Xuán Guǐ Zōng need the crossguard she is carrying to draw the Tiān Xíng Jiàn from its sealed pedestal. Not wanting to get involved any further, Bù Huàn takes his leave and goes into a town, where he learns that the Xuán Guǐ Zōng have labelled him as an enemy. He leaves town, passing by a stranger who warns him of an ambush further down the road. Exactly like the man warned him, the Xuán Guǐ Zōng's Liè Mèi confronts Bù Huàn and her lackeys surround him. Just then, Bù Huàn is joined by a warrior named Juǎn Cán Yún, along with the stranger from earlier, Shòu Yún Xiāo, who defeat Mèi's soldiers and force her to retreat.

Yún Xiāo and Cán Yún are revealed to be allies summoned by Guǐ Niǎo to join Fěi and a reluctant Bù Huàn as they journey to the Seven Sins Tower in the Demon Spine Mountains where the Xuán Guǐ Zōng dwell. Guǐ Niǎo explains that in order to get past the barrier surrounding the mountains and reach the tower, they must overcome three different obstacles, one of which requires the assistance of a demon necromancer named Xíng Hài, who resides in the Night Devil Forest. The next day, the group heads into the forest to seek out Hài, who believes them to be trespassers and attacks them with an army of zombies, which Fěi and Cán Yún fend off while the other three press forward.

Guǐ Niǎo uses fire to draw Hài out of hiding, managing to persuade her to join his party after bringing up the Tiān Xíng Jiàn. Meanwhile, Lián Qí, Guǐ Niǎo's master who possesses the Soul Echo Flute needed to make it through the labyrinth leading to the Demon Spine Mountain, is attacked and killed by the Screaming Phoenix Killer, Shā Wú Shēng. He steals the flute and awaits Guǐ Niǎo's arrival. Wú Shēng tries to provoke Guǐ Niǎo into fighting, but he refuses to do so. Instead, Yún Xiāo and Cán Yún attempt to fight against Wú Shēng but are both easily outmatched, prompting Guǐ Niǎo to call a retreat.

After the group returns to their inn, they talk about confronting the Screaming Phoenix Killer. Cán Yún is determined to fight Wú Shēng in a duel the next morning, because he considers himself expendable and because, if he wins, then he would make a name for himself. Xíng Hài offers her help in the form of spells. Guǐ Niǎo, however, feels that confrontation should only be used as a last resort. Bù Huàn gets tired of the talk and decides to head off on his own. He goes to the Devilwood Flower Garden himself and asks Wú Shēng to hand over the Soul Echo Flute. Wú Shēng refuses and they prepare to battle, but Guǐ Niǎo diffuses the situation and asks Wú Shēng the favor of becoming the performer of the Soul Echo Flute; in exchange, Guǐ Niǎo propositions Wú Shēng his head once they have reached the summit of the Demon Spine Mountains. Wú Shēng agrees. Meanwhile, Miè Tiān Hái suspects that Guǐ Niǎo's group will head to him.

Bù Huàn is worried that the group cannot work together, as everyone is suspicious of each other. However, he still accompanies them as they ride a boat to the Demon Spine Mountains. Upon arrival to shore, the group encounters the Xuán Guǐ Zōng, led by Liè Mèi and Diāo Mìng. Cán Yún is motivated by Wú Shēng to attack and takes care of the "cannon fodder," while Hài and Yún Xiāo work together to raise the dead created by Cán Yún. Wú Shēng finally attacks after all the soldiers have been taken care of, killing Liè Mèi. Suddenly, Miè Tiān Hái shows up.

After Miè Tiān Hái shows up, he mocks the group then immediately leaves, along with the rest of the Xuán Guǐ Zōng. The group then arrives at the Demon Spine Mountains, and rest a night before heading in. Dān Fěi is up practicing, when Cán Yún shows up and gives her a few pointers, though angering her in the process. She storms off and the group enters the mountains the next day, encountering the Valley of the Dead, the first trial. Xíng Hài is called upon to put the dead to sleep, but fails a few times; Fěi protects the group with her Hù Yìn Shī skills, except for Bù Huàn who has to fight the dead. Hài finally succeeds in singing the correct tune and the group moves on, arriving at the second trial, the Valley of the Doll. A golem guardian stands there motionless, and Bù Huàn activates it, allowing Yún Xiāo to fire at its weak point. Yún Xiāo misses twice, though, so Bù Huàn takes matters into his own hands and climbs the golem, stabbing the charm himself and deactivating the golem. He then falls off, but is saved by Yún Xiāo's arrow, which pierces through his clothing and nails him to the arm of the now-deactivated golem. The group then moves onto the final trial, the Labyrinth of Darkness. Bù Huàn, however, declares his departure before they can continue

After Bù Huàn storms off, Fěi admonishes the groups and runs after him. Guǐ Niǎo also follows her. The remaining four comrades decide to pass through the Labyrinth of Darkness using the Soul Echo Flute. Guǐ Niǎo and Fěi find Bù Huàn spying on some Xuán Guǐ Zōng soldiers, who are trying to catch more demon birds. The three of them ambush the Xuán Guǐ Zōng and use a bone-whistle to call the demon birds and ride them to the Seven Sins Tower. Once they arrive, they find Tiān Hái waiting for them. Fěi immediately attacks him, seeking vengeance for her brother and to obtain the hilt of the Tiān Xíng Jiàn. However, Guǐ Niǎo sprays Fěi with smoke, causing her to attack Bù Huàn instead. Diāo Mìng then knocks out Fěi and arrests Bù Huàn. They are then thrown into cages, where they are found by the other four. Yún Xiāo reveals Guǐ Niǎo's other name, Enigmatic Gale (Lüè Fēng Qiè Chén), while Fěi reveals his real name, Lǐn Xuě Yā.

Yún Xiāo and Xíng Hài reveal that their letters from Lǐn Xuě Yā asked them to swindle Fěi of her crossguard. Wú Shēng affirms this with the letter he stole from Xuě Yā's teacher, Lián Qí. Cán Yún is shaken up by this turn of events, but still follows the other three as they leave Bù Huàn and Fěi in their cells. Wú Shēng returns to the Tower, though, seeking Xuě Yā's head as promised. Meanwhile, Xuě Yā and Miè Tiān Hái are having a discussion about the Tiān Xíng Jiàn. Wú Shēng interrupts this discussion, though, and before going after Xuě Yā, challenges Tiān Hái to a duel. Tiān Hái slays Wú Shēng, and explains his swordsmanship to Xuě Yā. While this happens, Bù Huàn breaks out of his cell.

After Bù Huàn exits his cell, he sees Wú Shēng fighting through endless streams of Xuán Guǐ Zōng fodder. Bù Huàn picks up a sword from a dead soldier and continues searching the Seven Sins Tower for Lǐn Xuě Yā. He then spots Xuě Yā and Diāo Mìng, and hides. Bù Huàn confronts Xuě Yā after Diāo Mìng leaves. Xuě Yā then explains his plan to Bù Huàn, and explains that both Yún Xiāo and Xíng Hài are villains that would take the Tiān Xíng Jiàn for themselves. All Xuě Yā wants to do is make Miè Tiān Hái despair. Xuě Yā also reveals the hiding place of the crossguard—the Limitless Temple. Bù Huàn then meets with Fěi and tells her the plan and to stay in the cell. Meanwhile, Xuě Yā sets up a deal with Tiān Hái. Afterwards, Xuě Yā meets with Bù Huàn again and gives him a hood that changes his appearance to that of Xuě Yā. They then begin to carry out Xuě Yā's plan. At the same time, Cán Yún breaks Fěi out of her cell.

Bù Huàn, disguised as Xuě Yā, meets with Tiān Hái, who becomes very suspicious, and together with the Xuán Guǐ Zōng, ride their demon birds to the Limitless Temple. As this happens, Xuě Yā discovers that Yún Xiāo and Xíng Hài also met with Tiān Hái. He then goes to unlock the safe containing the hilt of the Tiān Xíng Jiàn, transforming his pipe into chopsticks. Erstwhile, after Bù Huàn receives the gold agreed upon for the crossguard of the Tiān Xíng Jiàn, he is questioned by Tiān Hái and Diāo Mìng, who have already seen through his disguise. Bù Huàn then acts as bait to allow Xuě Yā to finish his part. However, Tiān Hái had kept the hilt on him the entire time. Meanwhile, Cán Yún and Fěi also head to the Limitless Temple by way of a Spirit Tree. There, they find the crossguard before the others arrive. They were followed by Yún Xiāo and Hài, though, and are forced to fight. Yún Xiāo and Hài obtain the crossguard and force Cán Yún and Fěi to retreat. Xuě Yā, alone again, sets up a trap.

After escaping, Bù Huàn happens upon Cán Yún and Fěi. He learns Yún Xiāo and Hài stole the crossguard and intend to sell it to Tiān Hái. Suddenly, Diāo Mìng and the Xuán Guǐ Zōng show up and attack the three of them. Bù Huàn shows his true colors and fights with a wooden branch. After killing Diāo Mìng and the Xuán Guǐ Zōng, Bù Huàn explains his philosophy as the three of them head to the Duàn Jiàn Cí. Meanwhile, Yún Xiāo and Hài meet with Tiān Hái at the Duàn Jiàn Cí. After removing the sword from the pedestal, Yāo Tú Lí is revealed, the lost demon god. Hài then kills Yún Xiāo for trying to prevent the awakening of the demon god. Xuě Yā confronts Tiān Hái outside the Duàn Jiàn Cí after Hài leaves.

Xuě Yā duels Tiān Hái, with Xuě Yā crushing Tiān Hái's spirit. Because of this, Tiān Hái destroys the Tiān Xíng Jiàn, releasing Yāo Tú Lí from the binding. Bù Huàn decides to face Yāo Tú Lí. He defeats the demon god by channeling the power of one of the thirty-six swords he collected from his travels, and banishes the demon god to the far reaches of space, ending the threat once and for all. He leaves the sword in the care of Cán Yún and Fěi, and departs, but not before receiving a parting gift from Xuě Yā.