

Mortal Kombat X
Shinnok made his debut as the final boss in Mortal Kombat Mythologies: Sub-Zero. Since, he's been a playable character and the final boss in Mortal Kombat 4/Gold, and was also a playable character in Mortal Kombat: Armageddon.
In the beginning, when the realms were first created, Shinnok's lust for power grew, and he desired to rule Earthrealm. Using the power of his sacred Amulet, Shinnok weakened the dimensional barriers between realms, and attempted to take the realm for himself. Thus great war against Raiden and the Elder Gods ensued. Eventually, Raiden, with the aid of the Elder Gods, would defeat Shinnok, take his sacred Amulet, and banish him to the Netherrealm.
In the Netherrealm, Shinnok endured constant torture by its ruler, Lucifer. He remained in constant torment until he encountered the sorcerer, Quan Chi, who could travel between realms at will. Offering a place at his side, Shinnok asked for Quan Chi's assistance in overthrowing Lucifer to become the new lord of Netherrealm. In return for his assistance, Shinnok bestowed upon Quan Chi incredible power. During his time in Netherrealm, Shinnok began building his Army of Darkness, as well as forming the Brotherhood of the Shadow, a fanatical cult dedicated to worshiping the fallen Elder God. Shinnok appointed Quan Chi as leader of this group.
Eventually, Shinnok's desires to rule Earthrealm began to grow once more. However, in order to escape the Netherrealm, he would need his sacred Amulet. After centuries of searching, Quan Chi learned of its location, hidden in the Temple of Elements deep within the Himalayan mountains of Nepal. With the aid of the Lin Kuei warrior Sub-Zero, Quan Chi was able to acquire the Amulet. However, he delivered a fake to Shinnok and kept the true Amulet for himself.
After Shao Kahn's failed attempt to invade Earthrealm, Shinnok launched his escape from the Netherrealm, and invaded Edenia instead, capturing Queen Sindel and the Princess Kitana. However, his konquest was short-lived. Despite all his efforts, Shinnok was defeated by Liu Kang and the Earthrealm warriors who came to Edenia's aid. Quan Chi revealed to Shinnok that his Amulet was a fake and that he had no power. Afterward, Raiden banished Shinnok to the Netherrealm once again.
During the events of Mortal Kombat: Armageddon, Shinnok learned of the great power one could obtain by defeating the elemental Blaze atop the Pyramid of Argus. In order to help achieve this prize, Shinnok proposed an alliance with Raiden, to which the thunder God agreed. He also offered to free Onaga from his confines in the Netherrealm in exchange for his assistance. It was also revealed that Shinnok had been aiding Daegon on his quest to obtain this power, as well.
In his Armageddon's ending, it is revealed that Shinnok sent a clone of himself to assist to Daegon fighting against Blaze. However, it was this clone that defeated Blaze and gained godlike power equal to that of Shinnok. He now had to defeat his clone in order to conquer the realms.
Alignment:
Alignment: Evil
Mortal Kombat 4

Banished to the Netherealm for crimes committed against his once fellow Elder Gods, Shinnok is freed from his confines by Quan Chi. With the aid of a traitor he then is able to overtake the realm of Edenia. From there he wages a war against the Elder Gods and awaits a chance to enact revenge against the god who banished him there - Raiden.
Mortal Kombat X

Millennia ago, a battle raged in Earthrealm between Raiden, God of Thunder and Earthrealm's Protector, and Shinnok, a renegade Elder God who sought to konquer all of reality. Raiden was victorious, and he and Shinnok's fellow Elder Gods imprisoned him in the Netherrealm. Twenty-five years ago, Shinnok escaped his bonds and attacked an Earthrealm weakened from war with Outworld. Raiden and his fellow Earthrealm god Fujin were able to imprison Shinnok in his own Amulet. But there are other forces who seek to possess Shinnok's makeshift prison and use it as a source of power. Forces less than friendly to Earthrealm...
Mortal Kombat 4

Shinnok: For millions of years, I suffered in the bowels of the Netherrealm. You thunder God are responsible for my suffering. Now, the piteous mortals of Earth will pay for my grievance.
Raiden: You turned against your fellow Elder Gods. You betrayed your title. You deserve much worse.
Shinnok: But it's too late Raiden. I win! With the Elder Gods out of the way, I will take my rightful place as ruler of all eternity. I can already feel the power surging from within.
Raiden: You're mad!
Shinnok: Farewell, thunder God. Hahahahahaha...
Mortal Kombat: Armageddon

Shinnok had anticipated the elimination of all the kombatants present at the final battle. He sent his doppelganger to aid Daegon in defeating Blaze. But with Daegon's unexplained disappearance, the false Shinnok defeated the firespawn. The power of Blaze breathed life into him, making him as powerful as the real fallen Elder God. Shinnok must now face himself if he is to rule supreme.
Mortal Kombat X

Earthrealm belonged to Shinnok. It became the staging area from which he would finish his war on the Elder Gods, which began eons ago. The Elder Gods had lied to the denizens of the realms: They were not individual beings, but merely parts of a greater collective known as the One Being. Shinnok would merge the realms and awaken him. Whole once more, the One Being devoured the Elder Gods. Shinnok watched with satisfaction. This reality had finally come to an end.

Mortal Kombat: Armageddon