Warning: This article contains spoilers from The Bad Batch season 3, episode 6, "Infiltration."
Star Wars: The Bad Batch season 3 continues to bring back familiar faces, including Senator Avi Singh in episode 6, "Infiltration." With help from Captain Rex and his network of rebel clones, Senator Singh meets with Senator Riyo Chuchi.
Singh was first introduced in The Bad Batch Season 1, episode 10, "Common Ground." He is the senator of Raxus, a planet that was the Separatist capital during the Clone Wars.
When the Empire occupied Raxus after the Clone Wars, Singh refused to support the Imperial occupation and instead spoke out against the Empire. Through his protocol droid GS-8, who also returns along with the senator in Season 3, Singh hired Cid to extract him from prison.
Cid assigned this job to Clone Force 99, who successfully extracted Singh from Imperial custody. Rescuing and meeting a Separatist leader who cared for his people was an eye-opening experience for Clone Force 99 as they'd spent the Clone Wars viewing the Separatists as little more than mindless battle droids and soulless monsters.
Singh felt guilty about abandoning his people, but GS-8 and Echo helped him see that he couldn't help them at all if he remained a prisoner. The senator went into hiding and was not seen again until his return in Season 3, in which he is now taking action to help the people of Raxus and others across the galaxy.
Chuchi and Singh discuss the possibility of aligning against the Empire. Singh's deep Separatist loyalties and Chuchi's history with the Republic make their budding alliance a momentous and exciting possibility. They are forming the building blocks of what will become the Rebel Alliance years before the events of Star Wars Rebels and Andor when the Rebellion is still taking shape.
Republic and Imperial senators like Chuchi secretly rebelling against the Empire is consistent with Mon Mothma, Bail Organa, and Tynnra Pamlo being part of the Rebel Alliance. It's also consistent with the deleted scene from Revenge of the Sith that shows Padmé Amidala, Mothma, Organa, and other Republic senators planting early seeds for the rebellion.
What Star Wars has mentioned but hasn't explored as much are Separatists and Separatist leaders being part of the Rebel Alliance. In books and comics, the Separatists are a big part of the Rebels, but it's never been delved into much on screen. As Singh explains to Chuchi, the Separatist desire for independence makes revolution against the Empire a natural choice.
The Bad Batch is a story primarily about the clones and not about the formation of the Rebel Alliance. However, it is satisfying to see some of the foundations laid for it in the early years of the Empire and to see former republic and separatist leaders uniting, brought together by former republic clone soldiers. Singh and Chuchi speak of the need for unifying leaders, who will ultimately prove to be Mothma and Organa. Mothma's ability to unify the Rebel Alliance will hopefully be shown in the upcoming Andor Season 2.
Even though this is only the beginning of Singh and Chuchi's discussions, what they're doing clearly scares the Empire. They already sent one of their brainwashed clone assassins after the senators, and the assassin's capture is what pulls Clone Force 99 into this episode.
Singh's return has The Bad Batch proving once again there are no filler episodes. "Common Ground" was deemed filler by some in Season 1, but it wasn't due to the important lessons the Batch learned in that episode. "Infiltration" further proves this with Singh's return being integral to building the lore behind the Rebel Alliance, while also tying into the core story of the Bad Batch.