Wei (Warriors Orochi)

The Wei force refers to the mixed army exclusive to the Warriors Orochi series. The characters in this particular faction all follow a character who originated from Wei. As Orochi conquered the resistances against him, Wei was one of the armies determined to destroy the snake demon. Despite their efforts, their army was defeated and Cao Cao was declared dead by Orochi's men. The remaining forces were subjugated into Orochi's army. Cao Pi, Wei's designated leader, acts as a loyal general. Following Orochi's defeat, Cao Cao resumes command of the kingdom and personally explores their new surroundings.

Story
The first game has Cao Pi suppress Huang Gai's rebellion at Kuzegawa, where he recruits Xu Zhu and exchanges words with Xiahou Yuan and Huang Gai before releasing him. He then defeats Nobunaga Oda at Tian Shui where he captures and releases Huang Gai again. He is then partnered with Mitsunari Ishida, which Da Ji calls "a match made in heaven". He then captures Zhou Yu and Sun Ce at Xia Kou only to release them shortly after. He then moves on to defeat Xiahou Dun, Pang Tong and Xiahou Yuan at Yi Ling where he convinces them to join him. As time passes, he stages his own revolt against Orochi capturing Da Ji at Odawara Castle after defeating her illusion of Cao Cao and Sun Jian and also convinces Huang Gai to join their ranks. He first moves to Chen Cang where he defeats the Azai army and gets Nagamasa Azai, Gan Ning and Oichi to surrender. Cao Cao also returns after recovering in secret at Yamazaki, where he and Dian Wei save Cao Pi and Mitsuanri Ishida from Dong Zhuo's assault.

In the second game, remnants of Orochi's army quickly reform as Cao Cao decides to also build up his own force. Cao Cao, along with the mysterious woman Nu Wa, drift throughout the land, with Zhang He and Dian Wei acting as bodyguards for their lord. At Si Province, Kunoichi informs Cao Cao that an outlandish 'circus' of an army, led by a monkey, had approached. Cao Cao asks if Nu Wa knows anything about it, but she denies to know anything. During the battle, Cao Cao's army combats a force led by a monkey and Dong Zhuo, who hasn't seemed to change at much at all, save for the fact that he now took the position of a "monkey-handler". At Si Shui Gate, Cao Cao finds out that Nu Wa has been testing him, after they face Lu Bu, while absorbing the Xiahou Dun army. After the battle, Cao Cao is suspicious with the appearance of a mystical monkey which he finds out to be named Sun Wukong, Da Ji's involvement, and Lu Bu.

Nu Wa finally reveals that Da Ji has the intention of reviving Orochi, while Sun Wukong seems to be working towards the same goal. With the knowledge of a high level of danger, Cao Cao seeks to find any potential ally. He along with Cao Pi sent letters requesting for allies, and sent Zhang He with an artillery to form an alliance with Yuan Shao at Shizugatake. At the latter battle, Taishi Ci joins the Wei forces on orders from Wu as their reply to Cao Cao's request. Zhang He also devises a plan to use the inner hatred of the three Yuan brothers to turn on their father, and also subdues Jiang Wei when he finds out of the plan.

At Ji Castle, Toshiie Maeda and Magoichi Saika face a Date army, led by Sima Yi. Cao Cao, thinking this as an opportunity to defeat the enemy and gain allies, sends Xiahou Yuan to help them out. The plan works out in success subduing the Date army, while Yuan and Magoichi Saika make a sort of friendly rivalry. Toshiie Maeda, thankful for the rescue, asks for anything they can do to repay their saviors. Cao Cao leads them to be absorbed into his own army. In the aftermath, Nu Wa ponders deeply about Cao Cao. He successfully gained an alliance with Wu, absorbed two armies into his own, and was even able to see through Nu Wa. She remarks that Cao Cao is more fearsome and deadly than Kiyomori Taira, and if turned down the wrong path, will be almost unstoppable.

At Komaki-Nagakute, Orochi was revived by Kiyomori, though in a very weak state. Their army attacked a ferocious detail led by Cao Pi, though they still deliverance from a friend. Cao Cao was the one to bring relief, rushing through to come into contact with his son, who is thankful. From there, Pang Tong successfully burns enemy ranks down in the center of battle, leading to praise from Cao Cao. After defeating the army, as well as Kiyomori, the latter transports Orochi somewhere else for safe keeping. Nu Wa explains that Orochi needed a girl named Himiko to restore his power, to which Cao Cao is disappointed that the woman has been keeping secrets yet again. At Yamatai, the Wei army pursues Himiko. Unfortunately, she escapes before they could catch her, but only after recruiting Nagamasa Azai, Oichi, and the Asakura army, who responded to Cao Cao's call. Da Ji and Nu Wa have a short conversation, where Da Ji remarks on how time has changed Nu Wa, compared to Da Ji herself. Cao Cao captured Da Ji, but has Nu Wa "eating out of the palm of his hand". Da Ji tells Nu Wa that she should look "closer to home" to find the real threat.

At Tong Gate, Kiyomori makes one final stand against the Wei command. Xiahou Dun led an army against him. Enemies had kept on reviving themselves, greatly confusing Dun's forces. However, Nobunaga Oda, along with his own army, that included Mitsunari Ishida and Katsuie Shibata, raided the battlefield, defeating the sorcerers that were the base of the confusion, and slayed Kiyomori. Nobunaga Oda and Cao Cao celebrate after the battle, along with their armies, which stands for the unity of the Coalition. In the end, Kiyomori was just trying to stall time for Orochi's complete recovery.

During the final battle of Guan Du, a fully-resurrected Orochi, named Orochi X, led a giant infantry to the West, while Cao Cao led an army to the East of the battlefield. The Hero of Chaos and the Demon King stood, unfazed by the Serpent King's overwhelming presence. The Wei army gradually takes over bases and takes strongholds. Three garrisons are taken in the middle of the battlefield, inhabited and protected by three officers. A good amount of enemy officers come to take the garrisons back, but Cao Cao unleashes a rifle unit, which helps destroy all Orochi officers who came to reclaim the bases. After taking over most of the battlefield, two forces acted as reinforcements. One of them - The Wu Kingdom, led by Sun Jian. The other - The Shu Kingdom, respectively led by Liu Bei. Both armies responded to Cao Cao's call for allies. After an inspiring comment by Nobunaga, the Three Kingdoms unite to finally slay Orochi X for the second time.

After slaying the Serpent King, the generals of Wei gather around his corpse. Dian Wei, skeptical of his actual death, is comforted by a confident Cao Cao. Yuan Shao, after absorbing the effects of the death of Orochi, decides to invite everyone to celebrate. Everyone follows Shao, though Nobunaga Oda, Cao Cao, and Nu Wa stay with Orochi X's body. Nu Wa confirms Orochi is dead, while Cao Cao and Nobunaga laugh as Cao still found Nu Wa worried about the two. Nu Wa talks to herself, hinting that Orochi actually wanted the humans that lived in the worlds he fused, to have their own world.

In the third game, the Wei army begins its path of conquest, and Cao Cao has a very strong rivalry with Nobunaga Oda. At one point, a detachment of Wei forces, led by Cao Ren, assist the Wu army in cornering Kiyomori at Hefei, but Kiyomori uses his newfound powers to take control of many Wei and Wu officers instead. Later in their timeline, the Wei forces, led by Cao Pi and Sima Yi, managed to corner Da Ji at Tong gate. The two commanders would later lead the Wei troops at Hulao Gate, but were killed by the Hydra. In the following timeline, it is presumed that many of Wei's officers had now either become enslaved by Kiyomori, were killed or were separated from each other. Nonetheless, Cao Cao himself disappeared once more and could no longer be found, and many of Wei's officers perished one at a time. The largest group of remnants would end up joining Sima Zhao, who was accompanied by Wang Yuanji, Zhuge Dan and Zhang Liao at Ueda Castle, though Sima Zhao would leave to try and defend Odawara Castle, the other three officers would be killed in the ensuing battle at Ueda castle.

When Sima Zhao returns to the past with Da Ji, the Wei forces misinterpret her presence as an alliance, and attack the Coalition at Tong Gate. Although Cao Pi is defeated, he and Sima Yi are convinced of the intentions of the Coalition, and various Wei officers are sent to aid Sima Zhao in secret. Meanwhile, Cao Cao, who is unconvinced, defies the Coalition's march to Chengdu at Fan Castle, and is defeated by Ma Chao, who is reluctant to release his desire for vengeance. After his defeat, Cao Cao promises to help the coalition, and aids Liu Bei's retreat from Chengdu.

Through the coalition's meddling, Guo Jia is rescued, and Cao Pi and Sima Yi are also allowed to succeed over the Hydra at Hulao gate. The coalition, however, returns back to Tong gate in order to rescue Diaochan, and must fight the Wei forces once more. Cao Cao, later joins the rest of the warlords as they prove their mettle against Susano'o.

In Ultimate, many of Wei's officers rejoin the kingdom in the new timeline, but Wei is involved in numerous conflicts resulting from Kyūbi's scattered tails. Believing that the Oda had betrayed their alliance, the Wei officers attacked Nobunaga at Nanjun, but were repelled. Later, a fake Nagamasa convinces Ma Chao into attacking the Wei forces. Later, a fake Pang Tong induces the Shu forces to also attack Wei. Having had enough of these tricks, Cao Cao works with the other warlords to stop Kyūbi, and Cao Pi and Guo Jia play a major role in her final defeat at Odawara castle.

Leader

 * Cao Pi

Allies

 * Zhang Liao
 * Xu Huang
 * Xu Zhu
 * Zhang He
 * Mitsunari Ishida
 * Nene
 * Yoshimoto Imagawa
 * Diao Chan
 * Huang Gai
 * Xiahou Dun
 * Xiahou Yuan
 * Pang Tong
 * Zhen Ji
 * Oichi
 * Nagamasa Azai
 * Gan Ning
 * Dian Wei
 * Cao Cao
 * Da Ji

Subordinate Generals

 * Cao Zhang
 * Cao Hong
 * Cao Xiu
 * Cao Zhen
 * Yoshitsugu Otani
 * Yue Jin
 * Sima Shi
 * Hideie Ukita
 * Xu Shu
 * Han Hao
 * Hao Zhao
 * Zhong Hui
 * Man Chong
 * Li Dian
 * Xiahou De
 * Xiahou Ba
 * Xiahou Wei
 * Hidemoto Mori
 * Hiroie Kikkawa
 * Ekei Ankokuji
 * Gao Shun
 * Wei Xu
 * Song Xian
 * Hua Xiong
 * Sima Lang
 * Sima Zhao
 * Yoshikage Asakura
 * Han Dang
 * Kagetake Asakura
 * Satoie Gamo
 * Terumoto Mori
 * Naoyasu Akaza
 * Suketada Ogawa
 * Shigemasa Toda
 * Chuko Shimozuma
 * Tamehiro Hiratsuka
 * Naoyori Shinjo
 * Yoshitsugu Maeba

Warriors Orochi 2 (Orochi)
This list refers to the kingdom's ranks during Orochi's story mode.

Leader

 * Cao Cao

Allies

 * Xiahou Dun
 * Xiahou Yuan
 * Dian Wei
 * Xu Zhu

Subordinate Generals

 * Guo Jia
 * Xun Yu
 * Zhu Ling
 * Wen Pin
 * Sun Li
 * Cao Zhen
 * Cao Hong
 * Cao Zhang
 * Yue Jin
 * Hao Zhao
 * Man Chong

Leader

 * Cao Cao

Allies

 * Nu Wa
 * San Zang
 * Kunoichi
 * Yuan Shao
 * Jiang Wei
 * Taishi Ci
 * Magoichi Saika
 * Toshiie Maeda
 * Cao Ren
 * Katsuie Shibata
 * Nobunaga Oda
 * Xiahou Dun
 * Xiahou Yuan
 * Cao Pi
 * Zhen Ji
 * Pang Tong
 * Nagamasa Azai
 * Oichi
 * Mitsunari Ishida
 * Dian Wei
 * Zhang He

Subordinate Generals

 * Xun Yu
 * Jia Xu
 * Sun Li
 * Cao Rui
 * Yasumasa Sakuma
 * Katsumasa Shibata
 * Nagayori Hara
 * Katsumasa Fuwa
 * Yoshitaka Rokkaku
 * Zhu Jun
 * Han Hao
 * Huangfu Song
 * Masayasu Miyoshi
 * Liu Ye
 * Bian Xi
 * Xing Daorong
 * Xun You
 * Yuan Tan
 * Guo Tu
 * Xin Ping
 * Yuan Xi
 * Gao Gan
 * Xiahou Ba
 * Xiahou Wei
 * Toshitsune Maeda
 * Ujiyoshi Horinouchi
 * Cao Xiu
 * Kagekatsu Uozumi
 * Yoshimune Kawai
 * Cao Zhang
 * Nobutada Oda
 * Nagahide Niwa
 * Hanbei Takenaka
 * Tsuneoki Ikeda
 * Nobumori Sakuma
 * Xiahou Hui
 * Hidemasa Hori
 * Koroku Hachisuka
 * Yan Liang