Li Mo Jun/Spoilers

History
As a child, he bullied Li Mo Ying to the point of almost killing him multiple times: pushing him into a lake and requiring him to kneel in the hot sun were two such instances listed. He even went so far as to say of his brother: "It’s only a piece of trash, with such strength he can’t even be considered a person. Even if he’s beaten to death, serves him right! Even Imperial Father wouldn’t stand up for him!"

Auction
He is humiliated by the Owner of Thousand Treasure Pavilion before the auction by oppressing him solely with his aura and forcing him to sit in General seating. In addition, the Owner works with Huang Yue Li to throughly damage his pride and extort money from him by distracting Li Mo Jun as the auctioneer announced that the Profound Armor set that Li Mo Jun desires is to be bid in gold not silver; when he finds out he thought his steal for 3 million silver is actually 3 million gold he is extremely angry and almost steals the armor. Mo San stops him and instead he is forced to pay an additional 10 million gold and 3 million for the armor.Since Huang Yue Li speaks up for him still being able to purchase the armor, he thinks more fondly of her.

Peach Blossom Banquet
When Huang Yue Li she reveals her talent by defeating Bai Ruo Qi, he quickly seizes the promise made between the Emperor and Bai Liu Feng that "his strongest son would be married to the strongest woman" (implying that would be Bai Ruo Li who had not been born yet) to mean that He (Li Mo Jun) and Bai Ruo Li should be married. However, Li Mo Ying could not take their engagement and challenged Li Mo Jun to determine the "strongest son." In the subsequent fight with Li Mo Ying, Li Mo Jun uses the Brilliant Sword to attack Li Mo Ying's weakness - Huang Yue Li, who was in Li Mo Ying's arms. This made Li Mo Ying so angry that his counter attack shattered the Brilliant Sword and the pieces were lodged in his meridians and diatian. Thus, he was ultimately disabled with his meridians severed.

South Yue (Part 2)
Fortunately for Li Mo Jun, his sister Li Xue'er was able to find a 5th grade pill to restore his meridians. He plotted again Huang Yue Li and Mo Yi by robbing Thousand Treasure Pavilion and escaping to the Treasury. After Huang Yue Li dealt with Li Xue'er, she assists Mo Yi to capture the Imperial Tutor and Li Mo Jun. Li Jun reveals that his ultimate plan is to sell Huang Yue Li to a brothel. In return, Mo Yi follow the command of Huang Yue Li to sever his meridians again in an incredibly slow and painful manner.

After Li Mo Jun escapes the collapsing treasury with the Imperial Tutor, they blame Huang Yue Li. However, the Emperor is unaware of Huang Yue Li's talents and thus she is able to implicate the Imperial Tutor and Li Mo Jun of Treason. He thus has his status as the Crown Prince revoked.