- Mortal Kombat Trilogy: "Born of Kitana's former world of Edenia, Rain was smuggled away from the realm as a small child shortly after Shao Kahn's take over. Thousands of years later he resurfaced. His allegiance belonging to Kahn, he chose to betray his homeland rather than suffer at the hands of Kahn's extermination Squads."
- Armageddon Bio Kard: "Although the blood of Edenian royalty flows through his veins, Rain is a traitor to his realm. When faced with the prospect of death at the hands of Shao Kahn, he offered his allegiance to the emperor and betrayed his homeland."
- Armageddon: "The Edenian race is descended from gods. That is the reason for our longevity, our nobility, and our strength. But I am more than a distant relation to the deities of old. I am a direct descendant of Argus himself. Only recently have I discovered my royal heritage. Quan Chi, an emissary of Shinnok, revealed to me that I am entitled to great power and control of Edenia. My father hid my identity for fear it would complicate his plans for succession. He favored his sons Daegon and Taven and groomed them to one day replace him as Protector of Edenia. But he foolishly tied this plan to a quest to save the realms from Armageddon, leaving open an opportunity for me to seize the power that is rightfully mine. Though it seems the Forces of Light seek to steal the prize from me, Quan Chi has made plans to assure my victory. He and his allies will help fend off the Forces of Light as I make my way to Blaze. But before this final battle, I must ensure that Taven and Daegon cannot challenge my ascension. I will finish them both before they complete their quest."
Rain is from the ancient realm of Edenia. He hails as the child of Argus, Edenia's protector. It is currently unknown who his mother is, however Argus's shame of infidelity, caused him to exile Rain from his royal family. As a result, Rain was given to an unnamed, but key general, in the Edenian military. Rain is a demi-god, the son of a true god and an Edenian.
His actions may have began before the events of the 1st Mortal Kombat tournament, as depicted in Mortal Kombat: Deception's Konquest Mode. Rain appears in Mortal Kombat: Deception as a non-playable character and is involved in two separate side quests. One of which involves Rain asking Shujinko to retrieve the enchanted daggers of the royal Shokan family. Rain states that Shao Kahn has enlisted him to retrieve the dagger for his own purposes, but Rain actually plans on keeping it for himself. Although this quest ends in Jade knocking out Rain for his troubles, it is canonly believed that he did keep the dagger, as it appears as part of his wardrobe in Mortal Kombat: Armageddon.
Several years later, Rain mysteriously returned during the invasion of Earthrealm. He aided Kahn in his plans for the conquest of Earthrealm. Trained in the art of kombat, Rain fought whole-heartedly to destroy Earth's warriors but his ending has Princess Kitana informing him about the true death of his adoptive father; that he was killed by Kahn's own hands. Because of this, he joins the Earthrealm warriors. After being absent during an extermination squad attack, he embarks on a suicide mission to destroy Shao Kahn in order to prove his questioned loyalty. It is unknown if this ending is canon or not, as the ending does not state if Rain succeeded or not. Merely that he left the Earthrealm Warriors to embark on the quest. Or it could be that Kahn was defeated by Earthrealm warriors before Rain confronted Kahn.
As Rain has not appeared as a playable character during the events of Mortal Kombat 4, Mortal Kombat: Deadly Alliance, or a main portion of Mortal Kombat: Deception, his current whereabouts were unknown. However, during the events of Mortal Kombat: Armageddon, Rain learned of his true Edenian heritage. Quan Chi informed Rain that he is actually a direct descendant to Argus, the protector god of Edenia. Rain then started to refer to himself as a prince of the realm, as seen in Armageddon's Konquest mode, but he still chooses to fight on the side of evil, although he no longer serves Shao Kahn. He wishes to kill both his half-brothers Taven and Daegon in order to be able to win the ultimate prize and power promised from defeating Blaze. Rain confronts his older brother Taven in Arctika, but he is beaten in battle, eventually escaping in a watery portal.
- Mortal Kombat Trilogy: "Rain fights valiantly for the emperor Shao Kahn. But it would be Kahn's own step daughter, the Princess Kitana, who turns Rain against him. Like Kitana, Rain's origins also come from their former realm of Edenia. He learns that his father was once a general in Edenia's army and died at the hands of Shao Kahn himself. Enraged at the truth of his history, he joins Kitana in aligning with the Earthrealm warriors. But his allegiance comes under question when he mysteriously disappears during an extermination squad attack. To prove his loyalty, he embarked on a suicide mission to destroy Shao Kahn and end the menace once and for all."
- Armageddon: "The half-brother of Taven and Daegon, Rain, absorbed the power of Blaze and became a full god. I had not anticipated that the victor would be the son whose true identity I have hidden for so long. I bestowed the title of Protector of Edenia on Rain, but my pride in my son was misplaced. He uses his power to enslave Edenia. And now that I have ascended to Elder God status, I am forbidden to stop him."