Jacen is played in live action by Evan Whitten, who you likely most recently watched opposite Christian Slater in the Netflix chupacabra movie Chupa.
One other note about Jacen: his name is clearly a nod to Jacen Solo from the now non-canon Legends continuity of Star Wars. In that timeline, Jacen was the eldest son of Han and Leia. The character was created by Timothy Zahn in Heir to the Empire, one of the key inspirations for Ahsoka.
Genevieve O’Reilly as Mon Mothma
We should all be used to seeing the wonderful Genevieve O’Reilly as Mon Mothma at this point, as she’s been playing the character since 2005’s Revenge of the Sith, although her work in the Prequel Trilogy closer was excised from the theatrical cut. That said, she returned to the role in Rogue One and most recently in Andor.
In Ahsoka, she’s a bit further along in her political career. Since this show is set five years after Return of the Jedi, Mon Mothma is now the Chancellor, the leader of the New Republic. Of course, O’Reilly isn’t the first actor to play the Rebellion/New Republic figurehead in live action. That honor goes to Caroline Blakiston, who brought the character to life in Return of the Jedi.
Nelson Lee as Senator Xiono
Nelson Lee plays Senator Hamato Xiono, the politician who is at odds with Hera about what to do regarding Grand Admiral Thrawn’s impending return. Not only is his role in the episode just further proof that the New Republic is destined to commit many of the same mistakes as the Republic from the Prequels but Xiono is also a bit of an easter egg himself. After all, he is the father of Kazuda Xiono, the main character from the Star Wars Resistance animated series.
The blind sparring technique that Ahsoka uses to train Sabine at the start of the episode is known as “Zatochi.” That name is a reference to fictional blind swordsman Zatoichi, who was created by Japanese novelist Kan Shimozawa. The character really came into prominence in Japan as the protagonist of a very long-running, 26-movie series starring Shintaro Katsu between 1962 and 1989. He also starred as Zatoichi in a television series that ran for 100 episodes.