A long time ago in a galaxy far, far away....
Reva Sevander, known as the Third Sister, survived the massacre at the Jedi Temple and turned Darth Vader's own Inquisitorius into her means of revenge. She trained as a Jedi initiate under Yoda. During Order 66 she watched Anakin Skywalker cut down her clanmates, whom she thought had come to be saved by him. He stabbed her, and she lived by playing dead among their bodies. Years later she joined the Inquisitors, and she was ruthless and reckless enough to anger both the Grand Inquisitor and the Fifth Brother. Her plan was to deliver Obi-Wan Kenobi to Vader and strike while the Sith Lord was distracted. In 9 BBY she lured Kenobi out of hiding by arranging the kidnapping of young Leia Organa. She stabbed the Grand Inquisitor on Daiyu, captured Leia again on Mapuzo, and tracked the Hidden Path to Jabiim, which earned her the title of Grand Inquisitor. Her attempt on Vader's life there failed badly. He ran her through, stripped her of rank and left her for dead. She then learned about Luke Skywalker from a message meant for Kenobi and went to Tatooine to kill the boy. At the last moment she saw that she was becoming the man she hated. She returned Luke to his family, laid down her lightsaber on Kenobi's advice and walked away into an unknown future.
Reva Sevander is born. She is Force-sensitive and is taken into the Jedi Order as a child.
Reva trains as an initiate in the Jedi Temple on Coruscant, taught by Yoda, and comes to see her clan of younglings as her family.
During Operation: Knightfall, Master Minas Velti leads Reva's clan away from the clone troopers until she is killed. Anakin Skywalker, now Darth Vader, slaughters the younglings and stabs Reva. She survives by hiding among the bodies and later needs cybernetic repairs.
Reva escapes the Temple, consumed by survivor's guilt and a thirst for revenge. She joins the Inquisitorius as the Third Sister so she can get close to Vader.
As an Inquisitor she hunts Jedi and Force-sensitives on worlds including Pantora, Valo, Cerea, Boz Pity and Alsakan, while fixating on finding Obi-Wan Kenobi.
Reva goes to Tatooine with the Grand Inquisitor and the Fifth Brother. In Anchorhead she maims a local and threatens Owen Lars and his family to find Kenobi, and her fellow Inquisitors rein her in.
Defying her superiors, she hires bounty hunters to abduct Princess Leia Organa and bring her to Daiyu as bait for Kenobi.
Reva corners Kenobi and tells him Anakin is alive. When the Grand Inquisitor tries to take over, she stabs him and leaves him for dead, and Kenobi escapes with Leia. Vader promises her the Grand Inquisitor's post if she catches Kenobi.
She finds a Hidden Path safehouse and its escape tunnel, kills the waiting pilot and recaptures Leia.
Kenobi and Tala Durith rescue Leia from the fortress on Nur. Vader chokes Reva for her failure, but spares her when she reveals she planted a tracker in Leia's droid, L0-LA59.
The tracker leads the Empire to the Hidden Path's base on Jabiim, and Vader promotes Reva to Grand Inquisitor aboard the Devastator.
Reva leads the siege. Kenobi realizes she survived the Temple massacre and wants revenge. When she tries to kill Vader, he defeats her, runs her through and strips her of rank, and the surviving Grand Inquisitor is at his side. Lying wounded, she plays a message from Bail Organa that reveals Luke Skywalker's existence.
Reva attacks the Lars homestead on Tatooine and chases Luke into Beggar's Canyon. On the point of killing him, she sees herself becoming Vader and spares him.
She carries Luke back to Owen and Beru. Kenobi tells her she has not failed and is free to choose her own path, and she lays down her lightsaber and leaves to start a new life.
The Inquisitorius is gone by the time of the Battle of Scarif. What became of Reva is never revealed.