Sindel/Current Timeline

"We are bonded in death. You will join us...and I will give you a proper upbringing!"

- Sindel to Cassie Cage in Mortal Kombat X.

Biography

 * Mortal Kombat (2011): "The mother of Kitana, Queen Sindel was forced into marriage with Shao Kahn when he conquered her realm of Edenia. In an attempt to thwart the emperor's designs on Earthrealm, she sacrificed herself. Her suicide created a magical ward preventing him from setting foot there. But now the barrier has been dissolved. Sindel has been resurrected, her mind enslaved by Shao Kahn. Earthrealm's former ally has become a deadly threat."


 * Mortal Kombat 11: "The former Queen of Edenia will stop at nothing to keep her place. When threatened with the loss of her throne when Shao Kahn conquered her realm, Sindel betrayed her husband, and her people, to keep her privileged position. Now Shao Kahn's wife and Queen of Outworld, she enjoys power and wealth beyond most people's imagination. Good luck to anyone who tries to take it from her."

Storyline
Sindel's storyline begins 10,000 years ago when her kingdom was captured by Shao Kahn. She, realizing that she was threatened with the loss of the throne, she betrayed her husband King Jerrod and her people in order to maintain her privileged position. As Shao Kahn's wife and Queen of Outworld, she enjoys power and wealth beyond most people's imagination. Then-infant Kitana adopted by Kahn as his daughter shortly thereafter. But realizing that Shao Kahn is destroying too many lives and that he will not stop after the capture of her kingdom, she decides to commit suicide. Her suicide created magical custody for Earthrealm, preventing Shao Kahn from stepping there.

Mortal Kombat (2011)
Sindel is resurrected by Quan Chi, who was accompanied by Noob Saibot. While Sindel's suicide provided protection for Earthrealm, her resurrection causes the protection to dissipate, allowing Shao Kahn to proceed with new plans. After Motaro is killed by Raiden, Shao Kahn takes the souls from Shang Tsung's body (killing him in the process) and grants his queen/empress the power needed to defeat her enemies.

With the new powers of Shang Tsung's souls, Sindel leads the Lin Kuei cyborgs, along with Cyrax and Sektor, in an attack on the Earthrealm warriors. While the cyborgs are all defeated, Sindel attacks and kills almost all of the Earthrealm warriors, and fatally wounds her own daughter, Kitana. She then ignores her daughter's pleas before draining her soul. She is then challenged by Nightwolf, with the latter emerging victorious. Yet the shaman is forced to sacrifice himself to destroy the Outworld empress. Only Johnny Cage and Sonya Blade survive, but with major injuries. When Raiden and Liu Kang return from their visit with the Elder Gods, they find a dying Kitana. Kitana eventually dies from her wounds inflicted by Sindel while talking with Liu Kang.

In an attempt at stopping Shao Kahn, Raiden goes to the Netherrealm to plead for Quan Chi's assistance. The necromancer states that he already has all of the souls from the recent battles, which includes Sindel's soul.

Mortal Kombat X
As a corrupted revenant, Sindel participated in Shinnok's invasion of Earthrealm, and was one of the key figures in the assault on Raiden's Sky Temple. Just outside the Jinsei Chamber, Sindel attempted to kill Fujin with her Migraine fatality, only to be intercepted and defeated by Raiden.

25 years later, she does battle with the former revenant Jax in the Netherrealm, where she is defeated. Any chance Raiden has at restoring Sindel and the other revenant heroes to an uncorrupted form is lost when Quan Chi is killed by Scorpion.

After Shinnok begins corrupting the Jinsei, Sindel confronts Cassie Cage. Cassie asks whether she feels guilt for killing her own daughter Kitana, and Sindel replies that they have been reunited in death as a real family. She offers to give an undead Cassie a proper upbringing as well, but is refused and defeated.

When Cassie goes to confront Shinnok, Sindel helps the other revenants battle Cassie's allies. After Shinnok is defeated, she and her cohorts make haste and disappear back to the Netherrealm. She likely continues to serve Kitana and Liu Kang, the new rulers of the Netherrealm.

Mortal Kombat 11
Shortly before the events of the game during the war with Netherrealm, Raiden kills Sindel in the form of a Revenant.

Sindel is mentioned during the ambush on Shao Kahn, while he reminds Kitana that he kept her only to appease her mother. Sindel is mentioned again, while revenant Jade reminds Jax that sindel made quick work of him.

Ending

 * Mortal Kombat (2011) (Non-Canonical): "The spell that bewitched Queen Sindel had been broken. She did battle with Shao Kahn and slew him—punishment for the suffering he brought upon her and millions of others throughout the realms. She dissolved the sorcery that bound Edenia with Outworld and began restoring her realm to its former glory. The many races of Outworld were impressed. Not only had Sindel defeated Shao Kahn, but she had shown great leadership in chaotic times. They willingly offered her their allegiance. Under Sindel’s governance, the realms of Edenia and Outworld remain merged in spirit."
 * Mortal Kombat 11 (Non-Canonical): "In the beginning... Shao Kahn invaded Edenia, murdered my husband, Jerrod, and forced me to be his bride. That's the story, but it's a lie. One I told, lest I lose the faith of my subjects, or of my daughter, Kitana. The truth? Jerrod was weak. Destined to fail. By betraying him, I gain a better lover and the ultimate weapon... A conqueror to unite all realms and put them at my beck and call. Then Kronika upended history, and i found myself confronting a future in which I'd been dead for centuries. My so-called family had failed me in every way. Kitana broke my heart worst. Instead of uniting all the realms, she sought to liberate them. As if the Wastelands' savages could ever be more than serfs! Ever the caring mother, I had to discipline my little princess. And after that, I had to discipline a Titan... Now i have defeated Kronika. Outgrown Shao Kahn and Kitana. I have no more family. No more rivals. No more gods. I sit above them all, on a throne that unites all realms... and all realities. Whoever you are, wherever you are, when you are before me, kneel. For I am Sindel, Empress of Time, and you exist only to serve me..."