In Mortal Kombat 4, Kai is an African-American man roughly around 25 or 30 years old, with short black hair and long sideburns, with an athletic physique, and has white tiger stripes on his entire body. He wears a dark red headband, abdominal sash, belt, and shin guards, along with black baggy pants and martial training shoes, and a pair of grey spiked wristbands.
In Armageddon, he looks somewhat 10 years older, his primary costume is more armored, his hair is in cornrows and he has mustache and a beard. His alternate costume is based on his original MK4 appearance.
Kai was part of the White Lotus Society and trained with Liu Kang and Kung Lao. As a result, he has very nimble moves such as his Renegade Kick, and fire projectiles similiar to Liu Kang's, albeit slightly different in terms of execution like his Downward and Upward Fireball techniques.
- Rising Fireball: informally nicknamed "Downward Fireball", Kai shoots a fireball into the ground, juggling his opponent. This move can also be performed in the air. (MK4, MKG, MK:A)
- Falling Fireball: informally nicknamed "Upward Fireball", Kai launches a fireball into the sky, where it then slams down vertically onto his opponent's head. (MK4, MKG, MK:A)
- Air Fist: Kai rapidly soars into the air in a diagonal motion with one fist extended, intending to punch an airborne opponent. (MK4, MKG)
- Hand Stand: Kai moves into a handstand position and can kick his opponent's stomach or face. Kai can also rotate on one hand and spin his legs like propellers, kicking his opponent repeatedly. (MK4, MKG)
- Lunging Roundhouse: Kai lunges forward and delivers a very powerful roundhouse kick which sends his opponent flipping sideways a half-screen distance away. (MK4, MKG)
- Renegade Kick: Kai charges up and unleashes a powerful flaming kick that knocks his opponent down. (MK:A)
- Rising Heel: Kai ducks to the ground then slides, unleashing a powerful flaming kick that launches his opponent up and back. (MK:A)
- One into Two: Kai lifts his opponent above him and rips him/her into two pieces. (MK4, MKG)
- Headshot: Kai levitates in front of his opponent and diagonally throws a fireball at his opponent, exploding his/her head in a morass of gore and brains. (MK4, MKG)
Appearances in other media
Kai appears in the official Mortal Kombat 4 comic that was distributed with some versions of the game. He is first seen training with Liu Kang. Their activities are interrupted when they witness an object fall from the sky. Investigating where it landed, they discover the Wind God Fujin in a crater surrounded by demons. The two are able to rescue the God and soon learn from Raiden that these demons were Shinnok's servants. Raiden and Fujin return to Heavens to battle Shinnok's minions there, while Kai and Liu Kang join forces with the other Earthrealm warriors, and then they all travel to Edenia to stop Shinnok's evil plans.
In Mortal Kombat 4, Kai was designed to be a very quick and nimble character comparable to Liu Kang, but with his own unique type of projectile attacks that would summon up from the ground or fall from the sky. Motion capture for his moves was performed by Sultan Uddin. Concept art for an updated version of Kai can be unlocked in Mortal Kombat: Deadly Alliance, suggesting that he was once planned to be in the game. However, he would not return as a playable character until Mortal Kombat: Armageddon. According to his bio card, Kai's handstand special move is one of Ed Boon's favorite techniques for the character, and – had they the time to implement it correctly – it would have become Kai's fighting stance in Armageddon. In Armageddon's Krypt, pieces of concept art show two possible weapon stances for the character: a White Lotus staff and a machete blade. Both were dropped in favor of a spiked club, while the machete was later given to Kobra.
After beating the game with Kai in Mortal Kombat 4, his weapon will change to Raiden's Lightning Staff. He is the only character that will change weapons upon beating the game. This reflects his game ending in which he receives the staff in order to aid his journey to search for his soul.
A side mission in Mortal Kombat: Deception's Konquest mode revolves around Kai. After the player, as Shujinko, encounters Kung Lao in Earthrealm and discovers that all of the Shaolin monks have been slaughtered, the latter requests that Kai be found in Outworld so that he can return and help rebuild the monastery. When approached, Kai states that he had finished wandering Earthrealm and would only return once his explorations in Outworld were complete. He then gives the player Raiden's lighting staff to give to Kung Lao.
- In various development stages, the Machete, the White Lotus Staff, and the Lightning Staff were all supposed to be his weapons.
- Similar to how Liu Kang was based on Bruce Lee (who also had students), it is possible that Kai is based on Bruce Lee's private student, Kareem Abdul-Jabaar.
- In Scottish, Kai means "fire"; matching his ability to use flames.
Mortal Kombat: Deception
- Although he gives Shujinko the Lightning Staff to give to Kung Lao in Konquest mode, the player cannot do so.
Mortal Kombat X
- Kai was originally going to appear in the game's story mode, but instead he was replaced with Bo' Rai Cho. 
Mortal Kombat 11
- In one of Cassie Cage's texting intro when fighting against Fujin, Kai texted Cassie saying "The wind already blowing?" and Cassie replies with "Feels dead calm to me." with a sunglasses emoji.
- Instruction booklet of Japanese version of Mortal Kombat 4
- Kai Bio Card
- Mortal Kombat 4 Limited Edition Comic Book. 1998, Midway Games
- Kai's Bio Card. Mortal Kombat: Armageddon Premium Edition Bonus Disc, Midway Games, 2006.
- www.SultanUddin.com (2004). Retrieved on 2007-02-21.
- Krypt Koffin UL – Kai Sketch. Mortal Kombat: Deadly Alliance, Midway Games, 2002.
- Krypt – Kai's White Lotus Staff Sketch. Mortal Kombat: Armageddon, Midway Games, 2006.
- Krypt – Kai's Machete Sketch. Mortal Kombat: Armageddon, Midway Games, 2006.
- Kai's Ending. Mortal Kombat 4, Midway Games, 1997.
- Shujinko: "I too am a member of the White Lotus. Can you tell me what happened here? Where are all of the other Shaolin monks?" // Kung Lao: "Murdered. They were all murdered to satisfy Shao Kahn's lust for power." Konquest mode. Mortal Kombat: Deception, Midway Games, 2004.
- Kung Lao: "A fellow member of the White Lotus named Kai is still in Outworld. Please find him and tell him he is needed here to help to restore the Shaolin." Konquest mode. Mortal Kombat: Deception, Midway Games, 2004.
- Kai: "Take this staff to Kung Lao. It once belonged to Raiden. It might help him to rebuild the White Lotus." Konquest mode. Mortal Kombat: Deception, Midway Games, 2004.