We first met the Nightsisters of Dathomir in The Clone Wars animated series and it took no time at all for them to be established as a credible threat to the Jedi. However, after catching the ire of Count Dooku, General Grievous and the Separatists very nearly completely wiped them out.
Dathomir's Great Mother Talzin managed to escape and was later defeated by Mace Windu and, we kid you not, Jar Jar Binks. However, prior to that, she created a sword from magic which was powerful enough to deflect lightsaber attacks.
Only a few Nightsisters now remain, including The Great Mothers on Peridea and Morgan Elsbeth. The latter fell in battle while facing Ahsoka Tano, though she pushed the former Jedi to her limits with the Blade Of Talzin in hand.
Conjured up by The Great Mothers, it's clearly the same sword Talzin herself once used, making this a great bit of connectivity on Ahsoka showrunner Dave Filoni's part.
Ahsoka establishes that shortly after the fall of the Empire, Grand Admiral Thrawn used The Great Mothers to contact Elsbeth so she could bring them home. After years of plundering planets for resources, you might think she was loyal to Thrawn, but the finale established that everything she's done is for Dathomir, not the Empire.
Her sacrifice allows The Great Mothers to return to their home planet with thousands of what appear to be coffins and the prevailing theory is they're full of long-dead Nightsisters. If magic can now be used to resurrect them, the Nightsisters will live again.
We're not sure how their return would differ from the walking corpses in Stormtrooper armour but have to assume that going home means there's a greater chance of them taking on a less monstrous form. As for why Thrawn is helping them, we'd assume it's because he'd quite like an army of powerful Force-users on hand!
If raising the dead and conjuring the Blade Of Talzin is just a glimpse of what they can do, then the Empire will soon be more formidable than ever before and there's surely a chance Talzin will somehow also rise from the dead...
Set after the fall of the Empire, Ahsoka follows the former Jedi Knight Ahsoka Tano as she investigates an emerging threat to a vulnerable galaxy.
In addition to Rosario Dawson in the title role, the series stars Natasha Liu Bordizzo as Sabine Wren, Mary Elizabeth Winstead as Hera Syndulla, the late Ray Stevenson as Baylan Skoll, Ivanna Sakhno as Shin Hati, Diana Lee Inosanto as Morgan Elsbeth, David Tennant as Huyang, Lars Mikkelsen as Grand Admiral Thrawn, and Eman Esfandi appearing as Ezra Bridger.
Ahsoka was written by Dave Filoni, who executive produces alongside Jon Favreau, Kathleen Kennedy, Colin Wilson, and Carrie Beck. Directors include Filoni, Steph Green, Peter Ramsey, Jennifer Getzinger, Geeta Vasant Patel, and Rick Famuyiwa.
All eight episodes of Ahsoka are now streaming on Disney+.