In "The Decisive Battle of the Unrestrained Sword", the Exotic Golden Scorpion mission is a key side quest. This guide to the three lines of the Exotic Golden Scorpion in "The Decisive Battle of the Unrestrained Sword" aims to help everyone complete this task well. In fact, after obtaining the Exotic Golden Scorpion, players can choose to hand it over to three different NPCs, thus triggering three different storylines. Below is a detailed comparison and recommended choices for the three lines; only after seeing them can you decide which side quest to undertake.

1. Na Wu Line
If you want to trigger this side quest, defeat the Exotic Golden Scorpion in the Monkey Grove Cave, and upon exiting, encounter Na Wu. Choose "Gift" or "Exchange". After completion, you can obtain the Secret Manual of Sword Style Two (Gift) or Sword Technique + two bottles of wine (Exchange, increasing HP/True Qi limit). Additionally, you can gain 20 points of favor with Na Wu (Gift) or 25 points (Exchange).

After completing the Nanjiang side quest later on, you can obtain a first-grade accessory (enhances poison damage) and unlock Na Wu as a party member (a character proficient in both poison and sword skills). This side quest is suitable for players who want to pursue a poison damage build and can also aim for the perfect Nanjiang ending, though it requires sufficient favor with Na Wu. The downside is that you won't be able to obtain the Thunderbolt Heart Sutra Secret Manual.

2. Liu Mayi Line
Hand over the Exotic Golden Scorpion to Liu Mayi in Gusu City, and then be introduced to Doctor Shang, which will trigger this side quest. Upon completion, you can obtain the Sword Technique Secret Manual and the Five Spirits Scripture (increases HP and True Qi limits). You will also gain 15 points of favor with Doctor Shang and unlock one chance to save someone (can heal Leng Wuxing). Later, Doctor Shang can join the team as a healing support role.

3. Yuanjiang Line
To trigger this side quest, simply sell the Exotic Golden Scorpion to the Poison Merchant, Zhao, on the eastern shore of the Youyun Marsh. Upon completion, you can obtain the Fist Technique Secret Manual (less versatile) and then unlock the剧情涉及南疆霹雳门、碧波教等势力的长生殿剧情,后续还可触发人面鬼蛛任务(与杏林会线重复)。

To obtain different rewards, you can learn from the three lines strategy of the Exotic Golden Scorpion in "The Decisive Battle of the Unrestrained Sword". Because only by completing different types of side quests can you achieve the desired rewards, and there's also a chance to trigger subsequent quests, unlocking more characters or plotlines.
Note: There was a part of the text in the last paragraph that wasn't fully translated. Here is the corrected version:
To obtain different rewards, you can learn from the three lines strategy of the Exotic Golden Scorpion in "The Decisive Battle of the Unrestrained Sword". Because only by completing different types of side quests can you achieve the desired rewards, and there's also a chance to trigger subsequent quests, unlocking more characters or plotlines.
And for the line that was missed in the translation:
3. Yuanjiang Line
To trigger this side quest, simply sell the Exotic Golden Scorpion to the Poison Merchant, Zhao, on the eastern shore of the Youyun Marsh. Upon completion, you can obtain the Fist Technique Secret Manual (less versatile) and then unlock the Longevity Hall storyline (involving the Nanjiang Thunderbolt Sect, Bibo Sect, and other factions), and subsequently trigger the Human-Faced Spider quest (overlaps with the Apricot Grove Society line).