Cao Cao (Legend Heroes)

Cao Cao aka Legend Hero Xiahou Dun / Xiahou Yuan, originally named Taeoh, is an anti-hero turned antagonist in the Korean Tokusatsu series Legend Heroes. He was originally a police officer until the death of his mentor Wang Yun caused him to quit the force and becoming a vigilante by becoming a Legend Hero and joining the Dream Battle. Holding the belief that all evil in the world must be immediately perished, Cao Cao is eventually coaxed down a dark path by his contract Angel Sima Yi, using the power of the Dark Pentagon to become Legend Hero Kaiser before giving his body over to Sima Yi to become Dark Warlord Sima Yan.

History
Taeoh aspired to join the police force after he was saved by police officer Wang Yun when he was younger. Becoming a police officer himself, Taeoh was assigned to stop the Bear Family crime syndicate in their spree of thefts. Learning of Legend Heroes and the Dream Battle after the Bear Family boss Dong Zhuo revealed himself to be a Legend Hero, Taeoh teamed up with Legend Heroes Liu Bei and Gongsun Zan to take the Bear Family down.

Taeoh would later learn that Wang Yun himself was the Legend Hero Lu Bu. When Taeoh went with Liu Bei and Gongsun Zan to stop the Bear Family at their hideout, they discovered that Wang Yun had been blackmailed into serving the Bear Family after they kidnapped his daughter, Diaochan. While Wang Yun was forced to fight Liu Bei and Gongsun Zan, Taeoh went to go rescue Diaochan.

After saving Diaochan with the help of the defecting White Bear, Taeoh returned and gave Liu Bei and Gongsun Zan Diaochan to take her away while he and Wang Yun arrested Dong Zhuo. However, Dong Zhuo revealed he was wearing a bomb vest and threatened to detonate it if they got any closer to him. Dong Zhuo ended up accidentally activating the timer anyway and pleaded with Wang Yun to save him. Though Taeoh believed Dong Zhuo shouldn't be saved because he was a criminal, Wang Yun went to save him anyway, removing the bomb vest and tossing it a safe distance away. Dong Zhuo then used the opportunity to shoot and kill Wang Yun before taking the Lu Bu Hero Piece and running away. Right before dying, Wang Yun told Taeoh to work with Liu Bei.

Seeking to enter the Dream Battle, Taeoh learned from the Hua Xiong Hero Piece he had recovered from Dong Zhuo that he needed the name of a mythical hero in order to enter. Thus, Taeoh changed his name to Cao Cao, the "evil punisher", and received a Legend Changer and the Xiahou Dun and Xiahou Yuan Hero Pieces from Sima Yi.

Cao Cao then went to go set Dong Zhuo free and gave him back his Hero Piece so he could fight him in the Dream Battle. Unveiling his own Legend Hero form, Cao Cao fought and defeated Dong Zhuo, knocking him onto the side of a bridge. Despite the pleas of Liu Bei for him to spare Dong Zhuo, Cao Cao refused to listen and finished the crime boss off by shooting his Legend Changer and knocking him off the bridge.

Quitting the police force, Cao Cao began operating as a vigilante who tracked down criminals using Hero Pieces, even if said criminals had reformed like Tao Qian. During the Rainbow Event, Cao Cao completed all of the trials and chose Sima Yi to be his contract Angel.

When Dong Zhuo returned with the Lu Bu Hero Piece thanks to Zhang Jue, Cao Cao went to fight him again. He defeated Dong Zhuo just as Liu Bei arrived to plead with him again not to kill him but Cao Cao refused. To prove to Liu Bei that his idealism was unrealistic in the real world, Cao Cao beat him senseless and killed Dong Zhuo right in front of him. He then called Liu Bei for being weak and criticized him for not being able to protect his Angel Xu Shu before leaving the scene.

After Liu Bei unlocked the form of Legend Hero Imperial and used it to defeat Dark Warlord Lu Bu, Cao Cao became wary of his new power. Told by Sima Yi of a legend that the power of Imperial would destroy the Earth, Cao Cao was convinced by him that the only way to stop Imperial's power was to merge with the Dark Pentagon they had recovered from Zhang Jue to become Legend Hero Kaiser. He then had Sima Yi create the Dark Warlords Xu Chu, Xu Huang and Zhang Liao and sent them out to gather Hero Power from civilians in order to power his Kaiser form up. He later traveled to the Red Cliffs Martial Arts competition to absorb the Hero Power of the fighters competing in it.

Liu Bei soon showed up and fought Cao Cao but was easily overpowered by the Kaiser's power. However, regaining his courage to fight after Sun Qian showed up and defeated the three Dark Warlords, Liu Bei transformed into Legend Hero Imperial to confront Cao Cao again. In a climactic battle, Liu Bei defeated Cao Cao and purged the Dark Pentagon from him before destroying it, depriving him of his Kaiser form.

Brought back to Zhang Jue's laboratory by Sima Yi, Cao Cao was told by the Angel that the only other way to overcome Imperial would be for Sima Yi to use an Angel Piece to merge his power into Cao Cao at the supposed cost of his own life. Cao Cao agreed and allowed Sima Yi to use the Angel Piece to fuse into him despite the protests of his own Hero Pieces. But rather than use the Angel Piece to give his power to Cao Cao, Sima Yi used it to overtake and possess Cao Cao's body, allowing him to compete in the Dream Battle.

However, after being reminded of his time as a police officer by Liu Bei and hearing Diaochan's pleas, Cao Cao broke free from Sima Yi's control and expelled him from his body. Angry that he could no longer compete in the Dream Battle, Sima Yi summoned Legend King Deathlon to destroy the Earth out of spite. Summoning his own mecha, Cao Cao merged it with the mecha of Liu Bei and Sun Qian to form Legend King Eternity to fight Sima Yi and Legend King Deathlon in a Final Battle.

Despite the tremendous might of Legend King Deathlon, Legend King Eternity managed to overpower it and destroy it, causing Sima Yi to be destroyed as well. With himself, Liu Bei and Sun Qian as the only remaining Legend Heroes in the Dream Battle, Cao Cao offered up his Legend Changer to Liu Bei for him to break but Liu Bei refused and the three decided to settle it in one final battle. Liu Bei emerged victorious as was able to claim the Royal Seal.

Cao Cao later showed up at Liu Bei's dojo Dowon-kwan to enroll Diaochan in it. He ended up having dinner with Liu Bei, Gongsun Zan, Sun Ce, Mi Zhu and Master Lu Zhi.