Kai is a Shaolin warrior in the Mortal Kombat series, debuting in Mortal Kombat 4 and later re-appearing in Mortal Kombat: Armageddon. One of the few African-American combatants playable in the series, he was seen in his earliest appearance as a deuteragonist to Liu Kang, replacing Kung Lao from previous games.
In Mortal Kombat 4, he used a kukri as his main weapon, although this is changed to Raiden's lightning staff once the game is completed with him (as he is entrusted with it in his ending). In Mortal Kombat: Armageddon, he fights with the fighting style Moi Fah and a spiked club. Although he can summon fireballs like Liu Kang, he launches them in a way that they either rise from the ground or fall from the sky.
Like several post-MK3 combatants, his influence in the overall story is minimal and he only appears in few games in the series. He also does not appear in the series's alternate and New Era timelines.
Original and Alternate Timelines
Like Liu Kang and Kung Lao, Kai was once a member of the secretive White Lotus Society before traveling throughout Asia to learn techniques from several martial arts masters.
In the original timeline, he eventually encounters Liu Kang in America and trains under him to become a Shaolin warrior. During the events of Mortal Kombat 4, he assists Raiden's forces in their battle against the fallen Elder God Shinnok. After Shinnok's defeat, Kai ends his tutelage and wanders the world on a quest for self-enlightenment. Years later, he joins the Battle of Armageddon and dies fighting alongside the others.
In the alternate timeline, his presence is unknown, likely due to Liu Kang's demise prior to Shinnok's return.
After defeating Shinnok, Kai goes on a spiritual journey, pledging to wander the Earth until he feels he has reached enlightenment. As a sign of thanks and to help him on his journey, Raiden gives him his lightning staff.
After defeating Blaze, Kai finds himself psychically linked with Old Being. Taking the opportunity to better his knowledge, Kai goes into deep meditation and searches through the realms of the Old Being, an entity who is responsible for reality itself. During his meditation he witnesses several things, such as Shao Kahn's rise to power and his defeat by Liu Kang. When Kai looks to the future for knowledge, however, he sees nothing.