About the Elder Gods
The Elder Gods are the supreme deities of the universe. Whereas other Gods only have jurisdiction over a single realm and typically represent an element, the Elder Gods are more ethereal and have power in all realms. The vague faces of the Elder Gods seen in Mortal Kombat 4, and the appearance of Shinnok in the same game, suggest that natural born Elder Gods have blue-gray skin and a humanoid appearance. However, in a special Mortal Kombat 3 ending, the Elder Gods were shown to be huge. Another different source of their form is found in Deception's Konquest Mode where an inverted dialogue states that, in their purest form, the Elder Gods resembles the Mortal Kombat Dragon logo. Beings with this form can be seen in Onaga's unused ending picture found on Deception's Krypt, and in Armageddon's Konquest, where Taven finds an inscription of his father talking to dragon-shaped figures, that he states to be the Elder Gods. Their true nature and extent of their powers remain a mystery.
Before the realms of Mortal Kombat came into existence, there was the One Being, which comprised all of known reality. The Elder Gods waged war and created the Kamidogu, powerful weapons used to shatter the One Being. The Elder Gods then created the realms from its body, with Earthrealm as the center of power.
Even though the One Being was shattered, its divided mind plotted through exceptionally powerful individuals. It acted through Onaga at first and would later through Shao Kahn, both unaware of its manipulations. It also commands Onaga during Deception to fuse the Kamidogus into one, and apparently only Ermac is able to notice its vague presence.
The Elder Gods' rule of non-interference in mortal affairs that do not threaten their own existence was evident when Shao Kahn, Emperor of Outworld, merged Earthrealm with Outworld to reclaim Queen Sindel, in direct violation of the sacred rules of Mortal Kombat. Raiden begged the Elder Gods to stop Kahn, who was required by those rules to win ten consecutive Mortal Kombat tournaments before he could take Earthrealm, but the Elder Gods did nothing. Thus, the Elder gods show no signs of being truly benevolent or malevolent towards the various threats posed to Earthrealm. They usually only intervene if the villain of the game poses a threat to their own existence.
Their non-intervention nearly cost them their existence when Shinnok escaped from the Netherrealm and attacked them directly. Millennia earlier, they had cursed Shang Tsung to consume the souls of other mortals to maintain his existence, either not knowing or not caring that his need to devour mortal souls would lead to him learning the location of Shinnok's amulet. Eventually that knowledge would reach Quan Chi, who used it to free Shinnok and take the amulet for himself. Thanks to the intervention of Raiden, Fujin, and the champions of Earthrealm, Shinnok was stopped. For this, Raiden was rewarded by being made an Elder God himself.
However, Raiden soon shed himself of this status when the Deadly Alliance arose as a threat to Earthrealm. Divesting himself of Elder Godhood to lead his mortal friends into direct combat, this time Raiden's efforts were thwarted, with all of his allies either killed or disabled. The threat posed by the Deadly Alliance was rendered moot, however, when Onaga the Dragon King appeared at the scene where Raiden had just been defeated by the two sorcerers. For millennia Onaga had lain in wait from beyond death to be resurrected and complete his conquest of the realms. Raiden, Shang Tsung, and Quan Chi were unable to stop him. It drove Raiden to realise that he could neither trust the Elder Gods nor his mortal comrades. Most of all, Raiden was furious with the mortal Shujinko for being duped into aiding the Dragon King's return.
Ironically, this time the Elder Gods did interfere. Now aware of a direct threat to their existence, because Onaga had acquired all the kamidogu and the amulet, the Elder Gods summoned Scorpion to act as their champion and destroy Onaga.
In Mortal Kombat: Armageddon, it is revealed that the Elder Gods foresaw that one day the Mortal Kombat tournament would be corrupted, and that the participating warriors would become too powerful and too numerous, jeopardizing the safety and existence of the realms. They demanded a safeguard be put in place to prevent Armageddon. Argus, the protector God of Edenia, and his wife Delia, constructed a hidden pyramid and created an elemental warrior known as Blaze to watch over the Mortal Kombat competitions and judge when its participants became too dangerous. When the time came, Blaze would call out, awakening Argus's two sons, Taven and Daegon, who would challenge Blaze on top of the pyramid. Whichever son won the battle would become the new god of Edenia, and be given the power to decide the fate of every other warrior. Should one brother be victorious, the kombatants would be stripped of their power. Should the other be the victor against Blaze, the kombatants would be stripped of their lives. Elder God characters can be created, but the necessary parts must be unlocked in Konquest mode.