Raiden (sometimes known in console ports of early games as Rayden to prevent confusion with Raiden) is the god of thunder and a regular combatant in the Mortal Kombat franchise. He is depicted in the series as the protector of Earthrealm, with the ability to teleport, fly, and manipulate lightning. In some games, he serves as an instructor to the main protagonists.
Raiden is played by Carlos Pesina in Mortal Kombat and Mortal Kombat II, Michael Garvey in Mortal Kombat Mythologies: Sub-Zero. In the films, he is played by Christopher Lambert in Mortal Kombat (1995), James Remar in Mortal Kombat: Annihilation and Tadanobu Asano in Mortal Kombat (2021). He appears as a secret character in early arcade versions of NBA Jam : Tournament Edition (along with Reptile, Scorpion, and Sub-Zero), and as an unlockable character in Unreal Championship 2: The Liandri Conflict. (sometimes referencing the series in taunts, such as "You fight like Johnny Cage!")
Prior to the Tournaments
Millions of years prior to the Mortal Kombat games, he fought the rogue elder god Shinnok in a war that threatened to destroy Earthrealm. After being victorious, he banishes Shinnok to the Netherrealm and secured Shinnok's amulet of power in a secret location guarded by the gods of wind, fire, earth, and water. However, in Mortal Kombat Mythologies: Sub-Zero, the evil sorceror Quan Chi (with the help of the older Sub-Zero), stole the amulet and entered Netherrealm to bring Shinnok back. Unable to enter Netherrealm himself, Raiden instructs the older Sub-Zero to follow Quan Chi and retrieve the amulet. (which he accomplishes)
The Earthrealm and Outworld Tournaments
Raiden was then given a personal invitation to the Mortal Kombat tournament by its host, the evil sorceror Shang Tsung. (in which every tournament won by the massive Goro results in weakening Earthrealm's barriers to the invading force of the emperor of Outworld, Shao Kahn) Although he attended the tournament, it is unknown if he actually participated. After Shang Tsung's defeat in the hands of Liu Kang, Raiden receives a challenge from Shao Kahn for a new Outworld tournament. (in which the defeat of Raiden and the Earthrealm warriors results in the weakening of Earthrealm's barriers) Raiden advises Liu Kang, Kung Lao, and the forces of Earthrealm about Shao Kahn's intention. It is not known if he directly participated in the tournament.
Merging of the Realms
After Shao Kahn's initial defeat, he initiates a plan to merge the two realms via ressurection of the Outworld queen Sindel in Earthrealm. As Shao Kahn invaded Earthrealm and devoured millions of souls, Raiden protected a select few mortals. However, Shao Kahn counters by sending extermination squads to destroy any survivors. Due to the merging of the realms, Raiden could not participate as a god. He instead temporarily reliquinshed his status as a god and sacrificed his immortality. He leads the chosen warriors into battle, and (together with Liu Kang) defeat Shao Kahn once again.
The Forces of Light
After regaining his status as the god of thunder, Raiden was unaware that the amulet Sub-Zero retrieved from Netherrealm (before the first tournament) was fake. Quan Chi helps Shinnok escape and both escape to Edenia with the intention of conquering all the realms and the destruction of the Elder Gods. Raiden and the god of wind, Fujin, organize a group of Earthrealm warriors to combat Shinnok. Being victorious, Raiden is granted the status of Elder God, leaving the responsibility as the protector of Earthrealm to Fujin.
Against the Deadly Alliance
As an Elder God, Raiden could not interfere with the deadly alliance of Shang Tsung and Quan Chi. Disgusted, Raiden relinquishes his status as an Elder God and returns to being the protector of Earthrealm. After reuniting with his comrades in Shang Tsung's old island fortress, he leads them to Outworld to confront the two sorcerors. However, the forces of Earthrealm were slain, and Raiden was defeated. As the two sorcerors turned on eachother, they were confronted by the resurrected Demon King Onaga. In an effort to defeat Onaga, Raiden allied with the two sorcerors. In desperation, he used his godly energy to create a bomb in hopes of destroying Onaga. Onaga survived and took Shinnok's powerful amulet (used by Quan Chi) for himself.
Raiden's essence regathered in Earthrealm, but he became furious at how Earthrealm was treated by its inhabitants (particularly at how Shujinko was deceived into ressurecting Onaga). He vowed no longer to entrust the safety of Earthrealm to mankind. Instead, he chose to enforce the protection of Earthrealm and destroy all those who threaten it. Raiden reanimates the corpse of Liu Kang (who earlier was killed by the deadly alliance) to serve as his zombie enforcer. During the events of Mortal Kombat: Armageddon, Raiden makes a temporary alliance with Shinnok and Shao Kahn (who, in return, would spare Earthrealm).
Changing the Past
While battling Shao Kahn as the lone remaining warrior at the top of the pyramid from Mortal Kombat: Armageddon, Raiden sends a message to his past self just as he is about to lose that "He must win." This message is received by Raiden just prior to the tournament from the original Mortal Kombat. Upon receiving this message, an amulet belonging to Raiden begins to crack. The god of thunder tries to alter the flow of time to prevent the vision that he saw, but his efforts are continually either negated or have unintended affects. In managing to rescue Smoke from the Lin Kuei, for example, he leaves open a door for Sub-Zero to be captured and turned into a cyborg instead. As time marches on through the second tournament and eventually Shao Kahn's invasion of Earthrealm, Raiden becomes more confused and distraught as his efforts appear to be in vain; many of his allies are killed and his amulet continues to crack, until he finally understands what his future self had told him, "He must win" meant "Shao Kahn must win." Due to a loophole in the rules regarding Mortal Kombat, if Shao Kahn were to enter Earthrealm himself, it would be a direct violation of the rules, and he would be subject to punishment by the elder gods.
Though he realizes this truth, he is unable to convince Liu Kang, who has become convinced that Raiden is mad. He intends to stop Shao Kahn from entering Earthrealm himself. Raiden tries to stop him, but in his efforts, accidentally kills him. Forced to contend with Shao Kahn alone, Raiden receives the support of the elder gods and is able to defeat him. Raiden then rejoins with Sonya Blade and Johnny Cage, intent on rebuilding after the devastation.
Raiden becomes bored of Shang Tsung's sorcery, Goro's brute strength, and the weakness of the other competitors. He invites other gods to participate in Mortal Kombat, resulting in Earthrealm's destruction. Have a nice day.
By winning the Outworld tournament, Raiden destroys Shao Kahn (and his minions) and destroys the dimensional gates between Earthrealm and Outworld.
In order to exist in the merged realms of Outworld and Earthrealm, Raiden relinquishes his status as a god and his immortality. He leads the chosen Earth warriors into battle, eventually defeating Shao Kahn himself.
After defeating Shinnok and leading his forces of light into victory, Raiden is granted the status of an Elder God. In his place as the protector of Earthrealm, he chooses Fujin.
Earthrealm must be protected. Raiden abandons his status as an Elder God and remains on Earthrealm as the Thunder God.
Corrupted after releasing his god-like essence during the game's introduction, Raiden became disgusted with mortals. He kills Shujinko for unknowingly being a tool for the Dragon King Onaga (despite Shujinko undoing his mistake and destroying Onaga).
After Raiden defeated Blaze, his strength increased beyond that of the other gods. Using his new-found power, he destroys all the realms so that none would threaten Earthrealm again. (It is unsure in the ending if Earthrealm is destroyed, as nobody would threaten a realm that doesn't exist)
After the inter-dimensional conflict, Raiden returned to Earthrealm only to discover that exposure to the sun weakened him greatly. Quan Chi offers Raiden a jade-colored stone that replenishes his power in return of his sworn allegiance.
Even though Shao Kahn had been defeated much of his invasion force from Outworld still roamed free and had to be dealt with. To combat this threat Raiden recruits four warriors and divides his souls placing one part in each of them. Now Raiden can be in four places at once to combat the forces of darkness.
In both the original timeline and the rebooted time-line Raiden becomes a corrupted version of himself known as Dark Raiden. In the rebooted time-line he also has ownership of Shinnok's amulet and its powers.
Dark Raiden's priority is still to protect the Earthrealm, but he will no longer do this in a noble, passive manner, instead making deals with people he'd normally never trust or killing whoever he feels is a threat to Earthrealm.
In the original time-line Dark Raiden is formed when Raiden fails to defeat the deadly alliance (Shang Tsung and Quan Chi) and the three of them fail to defeat the resurrected Onaga in the intro to Mortal Kombat: Deception. Raiden attempted to take them all out in one mighty explosion of his essence (which killed the two sorcerers but Onaga survived thanks to the kamidogu). Raiden reformed physically in Earthrealm only to find that he had also been infused with parts of his three enemies.
In the rebooted time-line during Mortal Kombat X, Shinnok is successful in entering and corrupting the Earthrealm's lifeforce, the Jinsei. In order to reverse the process Raiden willingly enters the corrupted Jinsei, taking the corruption into himself.
Mortal Kombat Legacy
Raiden appears in the 6th episode in the first season of web series, Mortal Kombat Legacy. At the beginning of the episode you see him descend upon Earthrealm and land on the grounds of a mental facility. Since he is dressed in all white the grounds keepers assume he is a patient of the facility and keep him locked in a room. He begs for release to "Fight in the Mortal Kombat tournament or Earthrealm will fall." but of course that only makes people think he's crazier.
Raiden escapes the facility by befriending a fellow inpatient named Blue. She stabs him in the heart and he disappears and reappears in an alleyway in what appears to be a Chinatown. He grabs a straw hat off a nearby onlooker and walks away.