Bo' Rai Cho, although first introduced in Mortal Kombat: Deadly Alliance, has been the teacher of many great warriors, including the Great Kung Lao, Shujinko, Liu Kang, and Li Mei. He uses very unorthodox methods of fighting, such as vomiting and flatulence, and his preferred style is Drunken Fist. All these techniques combined make Bo' Rai Cho a very deceiving kombatant.
Because he is originally from Outworld, he never entered the Mortal Kombat tournament himself, since it would have meant competing against Earthrealm on behalf of the emperor Shao Kahn. Instead, he used his fighting prowess to train Earthrealm warriors without becoming directly involved until the Deadly Alliance emerged.
Upon hearing of Liu Kang's death, Bo' Rai Cho teaches Kung Lao the whirlwind kick in the hopes that this technique may help him defeat Shang Tsung. While the Earthrealm warriors were preparing to attack the Deadly Alliance, Bo' Rai Cho secretly entered Shang Tsung's palace to free Li Mei.
In Bo' Rai Cho's Mortal Kombat: Armageddon ending, he is transported to the heavens after defeating Blaze. Argus, seeing the good in him, makes Bo' Rai Cho a god and the new protector of Outworld.
Alignment:
Alignment: Good
Mortal Kombat: Deadly Alliance

During the years that Shang Tsung had sponsored the Mortal Kombat tournaments on Earth, the Outworld master Bo' Rai Cho was secretly training warriors for competition. It was even speculated that it was he who brought the fighting style of Drunken Boxing to Earthrealm. After many years, he finally discovered the Shaolin monk Liu Kang and taught him the martial arts moves he needed to defeat Shang Tsung. Later, with the tournament securely in the hands of the Shaolin, his teachings were no longer needed and he returned to Outworld.
Bo'Rai Cho had been unable to compete against Shang Tsung in the Mortal Kombat tournament on Earth. His Outworld birthplace guaranteed that his victory would have been in the name of Shao Kahn. But the conflict this time was not a tournament to prevent an evil emperor from consuming another realm. This time the battle was to save his own realm from the tyranny of two evil sorcerers. Nothing could hold him back from the challenge that lay before him. The wrath of Bo'Rai Cho would be unleashed once again.
Mortal Kombat: Tournament Edition

During the years that Shang Tsung sponsored the Mortal Kombat tournaments on Earth, the Outworld master Bo' Rai Cho was secretly training warriors for competition. It is even speculated that it was he who brought the fighting style of Drunken Fist to Earthrealm. After many years, he finally discovered the Shaolin monk Liu Kang and taught him the martial arts moves he needed to defeat Shang Tsung. Later, with the tournament securely in the hands of the Shaolin, his teachings were no longer needed and he returned to Outworld.
Mortal Kombat: Deception

I have dealt with Tarkatan warriors before. Baraka and his mutant thugs were easy to evade as I entered Shang Tsung's palace to rescue Li Mei. I had arrived not a moment too soon. I snatched her away from the Deadly Alliance and swiftly carried her to safety. An alarm was sounded, and hordes of Tarkatan warriors pursued us across the main bridge.
On the other side of the palace bridge, I was met by Earthrealm's thunder god, Raiden, and his band of heroes marching to battle the Deadly Alliance. I bid them a glorious victory, but my primary concern was Li Mei's safety. I have since learned of the disaster that took place at the palace. The Dragon King had indeed returned, as legends foretold. Without our Earthrealm allies, I fear for Outworld's future.
Mortal Kombat X

Bo' Rai Cho, Master of Kombat, is Outworld-born but sympathetic to Earthrealm. Thus he has spent his long life training Earthrealm warriors for their tournaments with Outworld. Bo's past students include the Shaolin monks Kung Lao and Liu Kang, the eventual champion of Mortal Kombat, and savior of Earthrealm. Recently, as the Outworld Civil War raged and a dangerous new weapon was revealed, Bo' Rai Cho sought to consult Lord Raiden to discuss strategy. So far his attempts to find his old friend have been unsuccesful.
Mortal Kombat: Deadly Alliance

Bo' Rai Cho looked gruff, but beamed inwardly. With their victory over the Deadly Alliance complete, he and Kung Lao had liberated Outworld from its latest threat. Despite the years that had passed since training his last student, his skills had proven useful once more. He was elated, but it would be most inappropriate to express such emotions in front of his newest apprentice.
Kung Lao invited his master to return with him to Earthrealm, to teach more warriors at the Wu Shi Academy. The success of his apprentice gave him renewed confidence in his training skills and, for the first time, a clear purpose in life. Bo' Rai Cho offered only token resistance. He accepted the offer because the defenders of Earthrealm could certainly use his help. But more importantly, because Earthrealm's rice wine put Outworlds liquor to shame.
Mortal Kombat: Deception

Onaga seemed invincible. The races of Outworld were in disagreement on how to deal with this threat, and Baraka's hordes were sweeping the land. Bo' Rai Cho had almost given up hope when he was visited by the spirit of his greatest student, Liu Kang. Their roles now reversed, Liu Kang gave Bo' Rai Cho the inspiration necessary to continue the fight.
Bo' Rai Cho's soul was invigorated! He met with Outworld's many leaders to forge a temporary truce. Kitana gave him command of what remained of her army, and he led them to battle against Baraka's mutant foot soldiers. The new army of Outworld crushed the Tarkata vermin, and Baraka himself was bested by Bo' Rai Cho's attack. The victory inspired the people of Outworld to rise up against the Dragon King.
Mortal Kombat: Armageddon

Upon defeating Blaze, Bo' Rai Cho was transported to The Heavens. He stood before me, a humble warrior unsure of his fate in the presence of a god. I had looked into his soul and found that he was a good man and a powerful warrior. Outworld needed a protector, a task for which Bo' Rai Cho had more than proven himself worthy. At my request, the Elder Gods breathed their life force into him, transforming the once humble warrior into a god. Bo' Rai Cho had become Protector of Outworld.
Mortal Kombat X

Having learned that Outworld was now protected by the Mortal Kombat tournament, Bo’ Rai Cho returned to defend his homeworld. He was no friend of Kotal Kahn, but no realm deserved subjugation. Bo’ Rai Cho began training Outworld warriors for the fight to come. With Bo’ Rai Cho’s fighting skills and leadership, Outworld repelled the Earthrealm aggresors. His former friend, Raiden, had been denied.