Rayden is the god of thunder who was assigned as the protector of the Earth realm by the Elder gods. Milennia ago, an Elder god named Shinnok became consumed by greed and attempted to take control of the Earth realm. As the Earth's protector, Rayden opposed Shinnok, and thus began a war that would last for centuries. The Earth was nearly destroyed and was plunged into darkness, but Rayden emerged victorious. He discovered that Shinnok had entered the realm using a magical amulet, and realized that with it, Shinnok could invade other realms. With the help of the Elder gods, Rayden stripped Shinnok of the amulet and imprisoned him in the Netherrealm. Rayden took the amulet, buried it deep beneath a spot in the Himalayan Mountains and erected a temple over it's location. He then appointed four protectors to guard the temple, each representing one of the four elements which made up the Earth realm. As long as the amulet remained on Earth, Shinnok would be trapped in the Netherrealm.
Thousands of years passed, and the Temple of Elements was forgotten. Rayden remained the Earth's protector, and was pleased that he had little to protect against. However, the Earth realm was once again threatened by Shinnok in the twentieth century. Shinnok's ally Quan Chi tricked a Chinese ninja named Sub-Zero into retrieving the amulet and delivering it to him. Sub-Zero was successful, and before Rayden could do anything about it, the amulet was once again in Shinnok's possession. Rayden confronted the confused ninja, and explained to him that he had been duped into aiding the would-be conqueror of Earth. Lacking any power in the Neatherrealm, Rayden sent Sub-Zero to Shinnok's palace in order to retrieve the amulet once again. Sub-Zero managed to recover the amulet and deliver it to Rayden, who destroyed it so that it would not fall into the wrong hands again.
Shortly thereafter, Rayden learned of a new threat to the Earth realm, that of the Outworld. A sorceror from this hidden realm named Shang Tsung had taken control of the once honorable Shaolin tournament, and was using it to collect the souls of Earth warriors. He extended a personal invitation to Rayden to compete in the tournament, and Rayden accepted. Taking mortal form to compete, Rayden realized the danger that Tsung represented. A young warrior named Liu Kang defeated Tsung, and Rayden was so impressed by his skill and determination that he later offered to act as a mentor to the youth. Having seen that the Outworld presence had been dealt with, Rayden once again returned to the clouds to watch over humanity.
Rayden witnessed Shang Tsung return to the Outworld and beg for mercy from his master, the evil Shao Kahn. He discovered that Kahn was luring Earth warriors into the Outworld to compete in a second tournament. After warning the survivors of the Shaolin tournament, Rayden himself journeyed into the Outworld, where he intended to personally defeat Shao Kahn. Although he fought well, it was Liu Kang who once again emerged victorious. It was believed that Shao Kahn's threat had ended, so Rayden returned to his watchful post.
However, Kahn was not quite finished. He managed to open a portal to Earth and began a violent invasion. The two realms began to merge, and because of this Rayden found himself unable to interfere, and thus he begged the Elder gods for their assistance. They refused his request, and Rayden once again shed his immortality so that he could exist on Earth. This was a risky move, but Rayden felt that his duty to Earth was more valuable than his own life. He gathered a band of Earth warriors which had survived the extermination squads and led them in an assault against Shao Kahn. Under Rayden's guidance, the warriors pushed Kahn's troops back into the Outworld, and the Earth returned to normal. After the great victory, Rayden returned to his post, and vowed to keep a closer eye so that he could avert crises before they happened.
A few years later, Rayden became aware that Shinnok was loose and threatening other realms again. Shinnok had taken over the Outworld to increase his power base, and from there had attacked the Elder gods themselves. Even though they had been unwilling to help during the Outworld invasion, Rayden knew it was his duty to help them in their time of need. Once again, he gathered a small band of Earth warriors to combat Shinnok. Though Shinnok possessed great power, Rayden's forces (aided by internal conflict among Shinnok's troops) emerged victorious. The Elder gods were so appreciative that they made Rayden an Elder god himself. Before departing the Earth realm, Rayden appointed Fujin as his successor, so that Earth would not be left unprotected.