Sinestro by Blood
Soranik was born to Thaal Sinestro and Arin Sur on the planet of Korugar. As a child, Soranik loved both her parents, but could definitely be described as a daddy’s girl. She adored her father and his green lantern ring. When he appeared on TV, she would excitedly call for him. However, a happy home life with her parents was never to be. As Thaal descended into dictatorship, Arin took her daughter and to live with the Natus, to keep her safe from the growing animosity that their family faced. Secretly, it was also to keep her away from Thaal. Arin refused to tell him where their daughter was and, eventually, he accepted her reasoning for keeping Soranik safe.

Rebellions rose against Sinestro and in their destruction, Arin was killed. In the end, Sinestro was ousted from his position of dictator, but his shadow would always remain over Korugar.

Natu by Name
Soranik grew up without his influence, but not without his presence. He would return in her teenage years and burn a mark — their family crest — across her face so that he would never lose her again. At her graduation, he disguised himself so that he could take her picture. Soranik remained blissfully unaware of his presence as she started her career as a doctor. To her, Dgibb Natu and Karoll Natu were her real parents, for she had never known any differently.

Green Lantern's Light
Like most Korugarians, Soranik grew up with a hatred for the green lanterns due to Sinestro’s rule over their planet. When a green power ring chose her, she tried to deny it, but with the life of a patient on the line she begrudgingly accepted its power so she could save their life. From then on, Soranik Natu served the Green Lantern Corps and patrolled sector 1417, which contained her homeworld of Korugar. Over time, she grew close to some of the other Lanterns, especially Iolande and Kyle. Overcoming her hatred of the green lanterns, Soranik thrived in her role and relished the opportunity to help others. She participated in the Sinestro Corps War, the Blackest Night, and at one point found herself kidnapped by the Weaponer in a plot to kill her father.

When Sinestro told her of her true parentage, it took a severe toll on her and made her question herself. Her hatred for Sinestro was so strong that she was willing to cast aside her morals if it meant his death.

Fears Made Into Light
After the War of the Lanterns and Sinestro’s disappearance into the depths of space, Soranik thought she was finally free to live her life and resume her duties. However, the yellow lanterns were still active, even without their leader, and continued to give the green lanterns trouble.

Arkillo, their current leader, kidnapped her, and the one to come to her rescue was Sinestro himself. On his return, he had also saved several Korugarians, and it was for them that Soranik first stayed. Sinestro regained control of his corps and focused on turning them into a force of order and to rescue displaced Korugarians. 

Just before the green lanterns disappear, Sinestro, with foresight of the future thanks to Lyssa, removes her ring and forcibly inducts her into the Sinestro Corps. Soranik is hardly happy about the turn of events but doesn’t have much choice. She remains with the Sinestro Corps and her father. It’s a tentative period of strange friendships and perhaps the start of closing the rift between her and Sinestro. Eventually, she is handed control of the Sinestro Corps, who have now replaced the green lanterns as the galaxy peace-keeping force.