Yin-Yang School

Yin-Yang School (Chinese: 阴阳家; Pinyin: Yīn Yáng Jiā), also known as the Yin-Yang Theorists, is a major antagonistic faction in The Legend of Qin, making full debut in Season 3 as its main antagonists. They are loosely based on the historical Yin-Yang theory supporters in China.

The Yin-Yang Theorists were seperated from Taoists five hundred years before Emperor Qin Shi Huang unified China and created the Empire of Qin. Focusing on the heavenly infinity upon humanity, their pursuit created several powerful spells and curses. However, its Crest of Yin-Yang Curse was lost in history for more than a century, along with the methods of curing it.

The Yin-Yang Theorists had grudge against Yan Kingdom and thus after the Emperor's unification, they became allied with the Empire against the Anti-Qin Alliance.

Leadership

 * Tai Yi the Eastern Emperor (Chinese: 东皇太一; Pinyin:  Dōng Huáng Tài Yī): The leader of the Yin-Yang Theorists and the main antagonist of Season 3. He is a mysterious individual with black robes and a mask. No one ever saw his true form or endured his real strength.
 * Sun - Dong Jun (Chinese:  东君; Pinyin: Dōng Jūn) / Yan Fei (Chinese:  焱妃; Pinyin: Yàn Fēi): Also known as the Top Female Mage of Yin-Yang Spells, Yan Fei is the former second-in-command of the house, the mother of Gao Yue, the wife of Prince Dan, as well as Yue Shen's archenemy. Once, she was on her mission of pursuing the Constallation of the Blue Dragon and spied at the side of Crown Prince Dan of the Yan Kingdom. However, she and Prince Dan fell in love for real and and escaped Qin Kingdom with him, before they married and gave birth to Jiru Qianlong (Gao Yue), their daughter. She became imprisoned by Yin-Yang Theorists after Yan Kingdom's downfall, sealed underneath the frozen prison beneath Shen Lou, and her existence became a taboo for the house.

Lead Guardians

 * Moon - Yue Shen (Chinese: 月神; Pinyin Yuè Shén): The current second-in-command of the Yin-Yang School, the archenemy of Yan Fei, Gao Yue and Tian Ming and the first Yin-Yang School executive to appear in the series. She acts as the Right Guardian of Tai Yi the Eastern Emperor, the primary leader of Yin-Yang Theorists, and an advisor of Emperor Qin Shihuang with abilities to perform prophecy. She is also a castor of Jing Tianming's curse, prophecizing him to be the slayer of his master Ge Nie, who had betrayed Qin Dynasty.
 * It was stated that her own family name in the animated continuty was Ji (Chinese: 姬; Pinyin: Jī), implying a relation to the king of Zhou Dynasty.
 * Star - Xing Hun (Chinese : 星魂; Pinyin: Xīng Hún): One of the youngest members of the organization and a child prodigy who was chosen to become the Emperor's personal warlock guardian. In spite of his young age, it was revealed that he had power stronger than all Five Elders.
 * He was theroized to be based on the historical statesman from Zhao Kingdom, known as Gan Luo (Chinese: 甘罗; Pinyin: Gān Luō), who was known for being a young prodigy in Zhao Kingdom. The non-canoncial spinoff comic stated his true name was Gan Luo, though the animated canon was yet to comfirm this.

Elders

 * Metal - Yun Zhong Jun (Chinese : 云中君; Pinyin: Yún Zhōng Jūn) / (' Chinese: '徐福; Pinyin: Xú Fú): Xu Fu is a taoist priest who is obssessed with the alchemy and the creation of elixir. He earned his trust of Emperor Qin Shi Huang via curing his headache, and told him about the legends foreign mystics. The Emperor entrusted him to be the catain of his ship, Shen Lou, which was used to discover the mystic land and secretly served as the prison for Yan Fei. Loosely based on the historical figure of Xu Fu.
 * Wood - Shao Si Ming (Chinese:  少司命; Pinyin: Shào Sī Mìng): Also known as the Priestess of Birth in English sub. A very mysterious character with little known background. Her face is covered yet she's said to be extremely beautiful. She has not spoken yet in the series. She is one of the top experts of Yin-Yang School. Her signature ability is Wan Ye Fei Hua Stream (Chinese: 万叶飞花流; Pinyin: Wàn Yè Fēi Huā Liú). She was previously part of the Five Elements Division (Chinese: 五灵玄同; Pinyin: Wǔ Líng Xuán Tóng).
 * Water - Lady Xiang (Chinese:  湘夫人; Pinyin: Xiāng Fū Rén) / (' Chinese: ' 娥皇; Pinyin: é huáng) & Nu Ying ('Chinese: 女英; Pinyin: nǚ yīng): 'Little is known about her background. In Lady Xiang's special edition, it is said that they are extremely similar twin sisters, whose personal names are Ehuang and Nuying, which are the names of Emperor Yao's two daughters, who both became the wives of Emperor Shun. The two sisters lived in Xiaoxiang valley (a valley where people only can enter but can't return). Elder is Ehuang and younger is Nvying. According to their stories one of the twin was dead. But doesn't know which one is dead or which one is still alive. They both fall in love with the same man at the same time –– Lord Shun. But when one of the twins died, he left the valley. She waits for her husband to come back to her.
 * ' Fire - Da Si Ming (Chinese: 大司命; Pinyin: Dà Sī Mìng ): Also known as the Priestess of Death in English sub. The Priestess of Death is a cruel and devious enchantress who hunts and kills anyone who stands against Emperor Qin Shi Huang, the First Emperor of China. Prior to the Emperor unified China, the Priestess was also the real murderer of Crown Prince Dan of Yan Kingdom, who was then the leader of Mohists as well as the mastermind of Jin Ke's assassination attempt, though the prince actually survived.
 * Earth: Lord Xiang (Chinese: 湘君; Pinyin: Xiāng Jūn) / (Chinese: 舜; Pinyin: Shùn): Little is known about his background. In Lady Xiang's special edition, his personal name is Shun,which is the name of Emperor Shun, a legendary emperor of Ancient China. He is the husband of the twin sisters. According to the special edition, the twin sisters jumped into the river in order to find out who was more loved by Lord Shun once they realized that love wasn't something that could be shared by two people. Unfortunately, Lord Shun only managed to save one of the sisters, and he doesn't know whether he saved Ehuang or Nuying. No matter which one is alive, Lord Shun was deeply in love with both of them and therefore losing one of the two sisters left him heartbroken. That feeling of guilt and heartbroken pain finally made him leave the Xiaoxiang valley.

Others

 * Jiru Qianlong (Chinese: 姬如千泷; Pinyin: Jī Rú Qiān Lóng) / (Gao Yue (Chinese: 高月; Pinyin: Gāo Yuè): A princess of the former Yan Kingdom and Yan Dan's daughter and an orphan, Yue Er possesses great talent in Yin-Yang techniques and is taken into the Yin-Yang School by Moon Goddess. She is told that her real name is Ji Ru (Chinese: 姬如; Pinyin: Jī Rú) and her courtesy name is Qianlong (Chinese: 千泷; Pinyin: qiān lóng), bearing the same family name as Moon Goddess.
 * Xiao Ling (Chinese: 小灵; Pinyin: Xiǎo Líng): Xiao Ling, a Taoist, attends the Yin-Yang School's Water Division in hopes of finding his long lost sister Xiao Yi (Chinese: 小衣; Pinyin: Xiǎo Yī). However, he was then executed by Shao Si Ming when his true identity was exposed by the Yin-Yang leaders, which were Donghuang Taiyi, Yue Shen, Xing Hun, Yun Zhong Jun and Da Si Ming at that time.
 * Five Elements Division (Chinese: 五灵玄同; Pinyin: Wǔ Líng Xuán Tóng): The Five Elements Division (Metal, Earth, Water, Fire, and Earth), composed of some of the most talented students in the Yin-Yang School.
 * Chu Nangong (Chinese: 楚南公; Pinyin: Chǔ Nán Gōng): An aging gray-haired man but wise, he is part of the Chu Kingdom and is one of the disciples of Li Is as well as a former member of the Yin-Yang School.