Star Wars fans have long speculated that Morgan Elsbeth could be a Nightsister, and that was confirmed in the first episode of Ahsoka, where she tells Shin Hati that the temple they’re in was built by her ancestors, the Nightsisters of Dathomir. When Shin calls her a witch, Morgan corrects her by saying she’s a “survivor.”
We don’t know a ton about Morgan, but we do know that she was an ally of Thrawn’s during the reign of the Empire. Exactly what that connection was remains unknown, but we also know that Morgan was a key asset in helping to build the Imperial navy on Corellia. Given Thrawn’s prominent position within the Imperial navy, as well as his interest in developing a new ship known as the TIE Defender, it’s easy to begin imagining ways in which their paths crossed. Once the Empire fell, Elsbeth wound up as the magistrate of Calodan, a city on the planet Corvus. She had an army at her disposal that included HK series assassin droids, bearing the markings of Thrawn’s 7th Fleet. It was here that Ahsoka Tano found her in The Mandalorian, capturing her and finding important information about Thrawn’s whereabouts.
But the first two episodes of Ahsoka make it clear that Morgan Elsbeth is a bigger threat than many expected, and we also learned that she is a Nightsister. The Nightsisters were an ancient clan of witches located on the planet Dathomir, and they could wield the Force through their use of magik. Having been around in the galaxy for a long time, the Nightsisters played a particularly significant role during The Clone Wars under the leadership of Mother Talzin. She was an early ally of Darth Sidious, but he wound up drawing her ire and taking her son, Maul, for his own apprentice. Later, a Nightsister named Asajj Ventress became Count Dooku’s apprentice, and after Dooku got rid of her, Talzin sent Maul’s brother, Savage Oppress, to be Dooku’s new pupil. The prevalence of Talzin and the Nightsisters in this period meant they had considerable influence – but enough so that Sidious saw them as a threat that needed to be removed.
As a result, General Grievous led an army of Separatist battle droids to attack Dathomir, and the Nightsisters and their home were devastated. Most of the Nightsisters were killed during this attack, and though Talzin survived, she was later killed by Grievous when she tried to kill Dooku and Sidious. The destruction of the Nightsisters was nearly total, but there were those who survived – such as Merrin, who stayed on Dathomir with the remnants before joining the crew of the Mantis alongside Jedi survivor Cal Kestis.
So when Morgan Elsbeth says she is a “survivor”, this is what she means. Her people are wiped out, and the Nightsisters of Dathomir as they were known for centuries are dead. But some have survived, and she is one of them. This ties in thematically with the overall series, because she is not the only survivor. Ahsoka Tano and Baylan Skoll are both survivors or an ancient order as well, as the Jedi Order fell a long time ago yet here they are. And even Sabine Wren is a survivor, a Mandalorian who was not wiped out in the Purge. These main characters are all survivors, but it matters greatly what you do with it.