Rain/Current Timeline

Mortal Kombat (2011)
In Mortal Kombat (2011), the official reboot of the series, which covers, and alters, the past events of Mortal Kombat 1-3, Rain was introduced as DLC. His original backstory as an Edenian orphan is retained, although in a modified form.

He bore witness to the invasion of his home world at the hands of Shao Kahn. During the chaos that ensued, Rain was smuggled away while his father stayed behind to perform his duties as a general in the Edenian army. Edenia's armies were crushed in the Outworld invasion, and Rain's father was subsequently killed by Kahn himself.

After that, he was rescued and raised by the Edenian Resistance following his adoptive father's death. He trained hard under their tutelage and turned into an elite, but arrogant fighter. He served the Resistance well for many years and he was denied his own command. Infuriated, he betrayed his own brethren and joined his mortal enemy, Shao Kahn, who promised Rain leadership of his own army.

Mortal Kombat X Comic
Though unseen, Rain was revealed in the seventh chapter of the online comic to have joined Reiko and Mileena in their war against Kotal Kahn. Rain proves to be an essential part of Reiko's plan in their ambush of Kotal K'etz and his forces, using his control over the weather to block out the sun, weakening the Osh-Tekk's powers before his confrontation with the Shokan Prince Goro.

Rain makes his first physical appearance in chapter eight. Upon spotting Kotal Kahn approaching, Goro orders Rain to once again manipulates the weather by blocking out the sun to deny Kotal Kahn his primary power source. But Kotal Kahn, armed with the power of Blood Magik granted to him by his Kamidogu, was not affected and severely burns Rain using the Sun God power. Rain is last seen on the ground, badly burned but groaning in pain, implying he survived his injuries.

Biographies

 * Mortal Kombat (2011): "A refugee orphaned by Shao Kahn's conquest, Rain grew up under the protection of the Edenian Resistance. An exceptional fighter, he soon rose through their ranks. As his reputation grew, so did his arrogance. When Rain demanded leadership of the Resistance forces, he was refused. Infuriated, he turned against his rebel comrades and betrayed them to their sworn enemy. In payment for this treason, Rain was promised his own army by the emperor Shao Kahn. Power would be his - no matter the cost... "

Endings

 * Mortal Kombat (2011): (Non-Canonical) "Shao Kahn had used Rain to crush the Edenian Resistance, but had not granted him an army. For this betrayal, Rain drowned the emperor in his own blood. A grateful Raiden thanked Rain for eliminating the emperor and saving Earthrealm. His heroics were befitting of a son of Argus. Rain's lost heritage was a revelation to him. That he was a direct descendent of an Edenian god, proved his superiority. Power was his by right. His divinity confirmed, Rain's path was clear. He would use Shao Kahn's army to rule not just Outworld, but all the realms. To Raiden's surprise and horror, Rain's first target is Earthrealm."

Character Relationships

 * Adoptive son of an Edenian general who was killed by Shao Kahn.
 * Rescued and raised by the Edenian Resistance following his adoptive father's death.
 * Betrayed the Resistance when they refused to make him their leader and joined forces of Shao Kahn.
 * Joined Mileena and Reiko against Kotal Kahn.