Warning - This article contains spoilers for The Mandalorian Season 2.
In the latest episode of The Mandalorian, we were introduced to a new antagonist: The Magistrate aka Morgan Elsbeth. She had taken hold of the city Calodan on the first moon of Corvus. There we saw her drain the natural resources and take the people in as slaves. In Ahsoka Tano's first live-action appearance, she explains to Din Djarin that she knew about Morgan Elsbeth and that she helped build the Imperial Navy after her home was massacred in the Clone Wars.
Later, we see her and the Magistrate go head-to-head in a lightsaber-beskar staff duel. We assume for most of the episode that Tano's motivation is to free the people of Calodan and put the Magistrate's rule to an end. However, when Tano defeats her, she puts one of her white-bladed sabers to her neck and asks, "Now tell me. Where is your master? Where is Grand Admiral Thrawn?" The scene cuts before we get an answer, but it clearly indicates that Thrawn is alive and still leading followers under imperial rule.
A hairstylist from The Mandalorian seemingly revealed where the Magistrate is originally from in an Instagram posted that has since been edited.
The original post called Morgan Elsbeth "one of the last survivors of Dathomir," which is a well known planet from Star Wars Jedi: Fallen Order as well as Star Wars: The Clone Wars.
WHAT THIS MEANS
Dathomir in Star Wars Jedi: Fallen Order is a dark planet on which main protagonist Cal Kestis had to fight undead Nightsisters who had initially perished during Order 66, just leaving one of their kind alive (that we know). Kestis also encountered a former Jedi who now wanted to use the power of the Nightsister against the Jedi. He is ultimately able to defeat the manipulated Jedi, but Dathomir had a very strong pull to the dark side.
It is unclear who exactly survived the attack on Dathomir during the Clone Wars, but it appears Morgan Elsbeth was one of them. This could open the door to her being a Nightsister. Even if she is not a proper Nightsister, Dathomir is filled with dark energy and it would be unsurprising for anyone from this planet to be an ally of the Empire.
At the end The Mandalorian "Chapter 13", is it unclear the fate of the Magistrate. With this apparent reveal, maybe she will have a role moving forward, or we could see our main characters visit Dathomir down the road.