Chi You (蚩尤, Chī Yóu) is a deity in Chinese mythology that descended from Shennong. This half-man, half-bull war deity helped and lead the Hmong and Li Tribes fight against the Yellow Emperor: the king who is said to be the ancestor of all Han Chinese. The Yellow Emperor lost many of his initial battles with Chi You but won the final battle with the invention of the South Pointing Chariot that allowed him to navigate through the thick fog summoned by Chi You's forces. Chi You was then beheaded by Yinlong (Winged Dragon), one of the Yellow Emperor's top generals.
He is worshiped in China as the god of war and weapons and, along with Huang Di, as one of the progenitors of the Chinese people. Shi Huang Di, the First Emperor of China, worshiped Chi You and attributed him to his success in conquering his rival states. Liu Bang, the founder of the Han Dynasty, was also noted to have worshiped at Chi You's shrine before his decisive battle with Xiang Yu.
He also plays an important part in the Miao and Hmong people's mythologies and folklore, regarded as a sagacious king, godlike warrior and leader, but also as their punishing downfall from grace. According to the tale, Chi You was betrayed by his closest general and all of the Hmong, and executed by the Yellow Emperor, after forbidding the practice of polygamy out of disgust and a need for order. Still alive after his body is dismembered and torn into many pieces, he forever cursed his people to exile, persecution, insurrection, disunity, suffering and the deterioration of their culture until they all repented and prayed for his forgiveness for their sin of regicide, dishonorable betrayal of ethics and carnal selfishness.
He is also known in Korea as Chi Wu Cheon Wang (lit. the Heavenly Lord Chi Wu), and some argued he was once worshiped as an ancestral god mainly by the people of Goguryeo (an ancient nation that shares ancestry with modern Koreans). Though this claim is unconvincing as it is only mentioned in the Hwandan Gogi (which was claimed to have been compiled in 1911) which is concluded as a false document.
Chi You was implemented in the July 2014 Kappa and the Temple of Doom Adventure event. Players could encounter him as a boss by gathering three Sankara stones and one fighting spirit to give to DB Katori. He could be summoned in any of the three event instances and spawned alongside a room of highly aggressive Tao Tie, Taown and Senri. As a reference to the myth, his boss form, Strength of a Thousand Chi You, used skills that inflicted the Misty Fog and Cloudy Fog ailments to increase player cooldown times, decrease their ailment resistance and decrease the strength of their almighty, physical and gun affinity skills. By defeating him, players have a chance of gaining the ability to fuse him in a triple fusion of Atavaka, Tao Tie and Taown.
"A Chinese god of war, often depicted with a bull's head, six or eight arms, and four eyes. He invented many weapons and commanded an invincible army. Seeking control of the land, he fought with Huang Di, and though he was winning, Huang Di invented the South-Pointing Chariot and defeated him. Huang Di had Chi You's head buried thousands of li apart from his body."
—Shin Megami Tensei IV compendium
Chi You appears as the third-strongest member of the Tyrant race. He can be recruited from the wild in Lucifer Palace or created through fusion, provided Flynn has reached level 87. There are no special requirements to summon him.
"A Chinese god of war, he is said to have invented many weapons. He and his followers rebelled against the Yellow Emperor, Huang Di, but were defeated."
—Persona Q: Shadow of the Labyrinth compendium
Chi You is the highest leveled Persona that can be obtained by beating an F.O.E. Once again, he is required to create the Quintessence Bow, Yukari's ultimate bow; he must be used in a sacrifice spread to obtain one of the materials, the others being a Tangled Thread and a Fire Ring Lump, Theodore requires to make it.