Asajj Ventress and Ahsoka Tano have been linked together for many years. Both fan-favorite characters made their canon debuts in Star Wars: The Clone Wars, although Asajj was first introduced in Genndy Tartakovsky's Clone Wars series, now part of Star Wars Legends.
After Leia Organa, Asajj and Ahsoka were among the first female Force-sensitive characters to have prominent onscreen roles in the franchise. With Ahsoka being a student of Anakin Skywalker and Asajj being a student of Count Dooku, they were natural rivals. But as time went on, Ahsoka left the Jedi Order and Asajj left the Sith behind, with both of them betrayed by the orders they'd served. The women even formed a tenuous alliance and helped each other out in The Clone Wars Season 5.
The parallels between Asajj and Ahsoka continue in The Bad Batch Season 3, episode 9, "The Harbinger." This episode mirrors Ahsoka's live-action debut in The Mandalorian Season 2, episode 5, "The Jedi."
"The Harbinger" and "The Jedi" bring back these The Clone Wars fan favorites in a new era for their characters, confirming their survival farther down the canon timeline. The Bad Batch is the first time Asajj is seen during the reign of the Empire, confirming that she was revived at some point after her death in the novel Dark Disciple by Christie Golden. For a character who has only been in stories set during the prequel era, there is something thrilling about hearing her say, "The Empire is more dangerous than you could possibly fathom."
"The Jedi" is not only Ahsoka's live-action debut but is the first time she appears during the reign of the New Republic, other than her very brief appearance in the epilogue of the Star Wars Rebels series finale. There is something surreal about seeing Asajj onscreen for the first time since The Clone Wars Season 5 when the series was still airing on Cartoon Network. It was equally surreal to see Ahsoka in live-action for the first time alongside Din Djarin and Grogu in The Mandalorian.
The parallels go further with what Asajj and Ahsoka actually do in their respective episodes. After explaining what M-count is to the Bad Batch, Asajj tests Omega to determine whether she is Force-sensitive and has a high M-count. Asajj gets to know Omega and care about her, as most do when they spend time with the enthusiastic clone.
Omega only passes one of the three tests Asajj gives her, and Asajj tells Omega what she's seen, leading her to believe that Omega doesn't have a high M-count. However, after Omega walks away with Wrecker, Asajj's interaction with Crosshair hints that she may have been lying after all.
Asajj makes it clear that if Omega were Force-sensitive, she'd have to be trained in the ways of the Force, a life that would take her away from the Bad Batch. Asajj seemingly lies to Omega and chooses not to train her despite her potential. Instead, she decides that it's best for Omega to stay with her found family for now.
In "The Jedi," Ahsoka tests Grogu and gets to connect with and know him. She is the one who tells Din and the audience for the first time that his name is Grogu, and she learns and imparts new information about Grogu's life in the years before he meets Din.
Unlike Omega, there is no question of Grogu's Force-sensitivity, with Ahsoka recognizing his enormous potential and that he needs to be trained, especially since he has spent a great deal of time since Order 66 suppressing his abilities to survive. Nevertheless, Ahsoka chooses not to train him. This decision is largely rooted in her trauma and regret, feeling as though she failed her teacher, Anakin, and that she later failed her own student, Sabine Wren. There is also the matter of Grogu's strong attachment to Din, with Ahsoka knowing all too well how such an attachment can lead a Jedi to the dark side.
Despite the connections and potential they see in the individuals, Asajj and Ahsoka do not proceed with training. Instead, they let Omega and Grogu stay with their respective found families, deciding that is best for now. But they also open the door for another future, with Asajj being the first to make the Batch see that as Omega grows up, she will one day need to leave them. Asajj seems to understand that this is not what Omega needs right now, but it will be what she needs one day.
By telling Din to take Grogu to the seeing stone on the planet Tython and to reach out to other Jedi there, she opened the door for Grogu to be trained by Luke Skywalker. This was an important and needed chapter in Grogu's journey, but it was only a chapter, with The Book of Boba Fett proving that Grogu will be staying with his found family for the indefinite future.
Omega seems to be on a different trajectory, with "The Harbinger" setting up that she has a unique identity and journey that means a future beyond the Batch. As Yoda says to Luke in The Last Jedi, "We are what they grow beyond. That is the burden of all masters." The Batch have taught Omega a great deal and have been integral to her development. However, she is nearly ready to grow beyond them, a burden they will have to accept and carry.
As for Asajj, she may or may not factor into the futures of Omega and Ahsoka. Asajj could train Omega in Tales of the Jedi season 2. With both Asajj and Ahsoka alive during the reign of the Empire, there is a possibility they could meet and possibly help each other out again, both survivors of a war where they were meant to die as pawns. Depending on how long Asajj survives, there's even a chance of a reunion during the New Republic era. But for now, it was just nice to get Asajj back and to have her Bad Batch debut mirror Ahsoka's Mandalorian debut.