As one of the most recognizable symbols of Star Wars, the Inquisitor lightsaber made them distinct from normal Sith lightsabers. Their unique shape made them an effective tool for spreading fear and intimidation. They were always feared by those who opposed them.

The hatred between Inquisitors and Jedi is rooted in Palpatine's manipulation of Force-sensitive individuals to create an army of warriors. This led to a reign of terror where Jedi were hunted, tortured, and killed. The Inquisitors' fear over the power of the Jedi drove them to seek revenge against those they blame for their loss.

The Grand Inquisitor. Before turning to the dark side, he served as a Jedi Temple guard. The other one is Bil Valen, also known as The Sixth Brother, after he turned to the empire side.

The exact number is unknown. But a widely accepted number is around fifty to sixty Jedi turned to Inquisitor during the Galactic Empire time.

Once, the Grand Inquisitor engaged in lightsaber combat with Ezra Bridger and Kanan Jarrus. Despite his formidable skills and power, Jarrus emerged victorious in the duel. Rather than face the consequences of his failure from Darth Vader, the Grand Inquisitor chose to end his own life by plunging into an abyss.

So we can say that Kanan Jarrus and Ezra Bridger can be credited with killing the Grand Inquisitor.

Reva, also known as the Third Sister, is considered the weakest. She also got mocked by the Grand Inquisitor as "the least of us." But as we can see in "Obi-Wan Kenobi," her awesome lightsaber combat ability and excellent tactical insight made the Third Sister quite far from weak.

Darth Vader disliked the Inquisitors; he had a deep-seated contempt for them and never accepted them as equals. Sometimes he may think them an obstacle to his plans. So, as a result, Vader allows the Inquisitors to remain in his system, but he never truly trusts or respects them.

Absolutely. The Inquisitors are chosen by Darth Vader because of their Force-sensitive ability. They normally use lightsabers as weapons, which you can see clearly on this page.

There are four of them that Obi-Wan Kenobi has, they are the Grand Inquisitor, the Third Sister (Reva), the Fourth Sister, and the Fifth Brother.

The answer is NO. The Star Wars series revealed that the Third Sister was named "Reva," trained as a Sith assassin by Vader. She was then tasked with hunting down Jedi, but she finally turned away from the Sith side and wanted to turn to the light side. But Vader sensed she was no longer loyal and tried to eliminate her. From all these, we can conclude that she is not a Sith.

Given to Inquisitors, the title of Brother&Sister didn't refer to any blood relationship between them. But it indeed fostered a sense of unity among the so-called brothers and sisters. From this, the Inquisitors could draw strength from knowing that their brothers&sisters were with them, making them more confident of getting their job done.