As the Third Sister, she was highly ambitious. Thus, her mind was set on tracking down Jedi Master Obi-Wan Kenobi, with her fellow Inquisitors assuming she hoped his capture would gain her Darth Vader's favor and therefore improve her station.
Stuart Beattie's original script for Obi-Wan Kenobi before he was replaced with Joby Harold had Darth Vader killing the Third Sister, who didn't know that he was Anakin Skywalker. She is currently the only Inquisitor to survive a direct battle with Darth Vader.
After Reva and her fellow Padawans fell victim to Anakin Skywalker/Darth Vader during Order 66, she wants to take revenge against the Sith Lord.
The reason why the Third Sister hates Obi-Wan Kenobi so much is because she was a Jedi initiate when Order 66 happened. On that infamous day, Reva was training with her fellow Jedi younglings in the Jedi Temple of Coruscant.
She wanted revenge on the Jedi for not protecting her and revenge on the Sith for what they did to her friends.
Cere Junda was a female human and a Jedi during the Clone Wars. She took on Trilla Suduri as her apprentice and the two survived Order 66. Suduri turned to the dark side and became the Inquisitor known as the Second Sister. Junda became a mentor to another survivor of the purge, Cal Kestis.
Former Imperial Inquisitor Reva (Moses Ingram) was left for dead by Vader after she tried to strike the Sith Lord down.
She's had to do all this and become a Sith, and by the end of “Part V”, she is impaled by Vader, who leaves her for dead. And Vader reveals that he's been aware of Reva's deception the whole time.
Before she became a Jedi hunter, she had possession of a droid. However, it was taken away from her, like many of her past belongings and acquaintances. During her time as an Inquisitor, the Third Sister wore black armor with a cape, and wielded a red-bladed Inquisitor lightsaber.
Designers decided that the semi-circle version would telescope out to create the full circle. Moses Ingram, the actor who played the Third Sister, received the lightsaber as a gift from Lucasfilm president Kathleen Kennedy.
Reva knows that Anakin Skywalker is Darth Vader because she was one of his targets—a child—during the Order 66 killings that took place during the events of Star Wars Episode III: Revenge of the Sith.
As Reva, the Third Sister, revealed earlier in the episode, she faked her death to cheat Anakin Skywalker the first time. However, it seemed that Darth Vader might have left her alive on purpose this time. Instead of giving Reva a fatal hit in the chest, Darth Vader only severely injured her.
She either saw Anakin kill her fellow Jedi or saw the recording of his crimes. That's why she has such hatred for Obi-Wan. She was a Padawan who escaped Order 66.
Reva was a Jedi youngling who was present in the Jedi Temple during Order 66. When the clones raided the temple, Reva and her fellow younglings found Anakin Skywalker and asked him for help, only for him to kill them all. Reva survived by playing dead, and she swore revenge on Anakin.
Trilla Suduri, also known as the Second Sister, was a Human female who served the Jedi Order as a padawan to Cere Junda.
Trilla Suduri was a tall, slender human female with light-brown skin, blue-green eyes and sleek black hair. During her time as a Padawan, she was kind and compassionate, caring for her master and the younglings under her protection.
The Fourth Sister was a female humanoid Inquisitor of the Galactic Empire.
The original script for the “Obi-Wan Kenobi” film, before it became a Disney+ series, included Reva's death. Writer Stuart Beattie told The Direct that Reva, played by Moses Ingram, was going to fall by Darth Vader's lightsaber at the hands of actor Hayden Christensen, in order to save Obi-Wan (Ewan McGregor).
In the denouement of the episode, after Darth Vader accuses Reva of failure, she reveals that she actually wanted Obi-Wan and Leia to escape. Reva let them go on purpose, and at this moment, Vader and Leia both learn valuable lessons.
The Seventh Sister was a female Mirialan Inquisitor who served the Galactic Empire and operated as a Jedi hunter in the years before the Battle of Yavin. She was tasked with tracking down Ahsoka Tano, a prominent figure in the rebellion against the Empire, by the Sith Lord Darth Vader.
He knew that her need for revenge had blinded her, which meant he was able to manipulate and use her for his own ends.
Former Imperial Inquisitor Reva (Moses Ingram) was left for dead by Vader after she tried to strike the Sith Lord down. She's too angry to die though and seemingly figured out that 10-year-old Luke Skywalker (Grant Feely) is Vader's secret son and living in hiding on Tatooine.
The Fourth Sister was a Force-sensitive female member of the Inquisitorius during the Imperial Era. During the imprisonment of Rebel Alliance Lieutenant Thom Hudd, the Fourth Sister was impersonated by Rebel Commander Lina Graf, who managed to rescue Hudd.
This information comes to light form the comic series Darth Vader: Dark Lord of the Sith by Charles Soule and Giuseppe Camuncoli, in particular issue #7. Palpatine admits to Darth Vader that the Jedi he actually feared most was none other than Jocasta Nu.
The Younglings Reminded Anakin of How Different He Was
Those negative emotions also power the dark side, meaning Anakin likely felt stronger as he killed the younglings. That, in turn, reinforced his belief that only the dark side could save Padmé.