6 BBY - Onderon, the first Rebel base

After escaping Crait, Rex now flies to the first Rebel base on the planet Onderon in the Imperial Gunship he previously stole before fleeing Lord Vader. Upon touching down next to the Rebel base, Rex saw Ahsoka talking to a green-skinned Twi’lek just outside the doorway, until he opened the Gunship doors and got out of the Imperial craft.

The sound of the Gunship doors opening managed to catch Ahsoka’s attention, as she turned her head and saw Rex walking towards her, before she turned to the green Twi’lek. “Excuse me for a moment..” 

The Twi’lek nodded, before she walked towards Rex. “Commander Tano! I have learned a terrible truth. I have learned that General Skywalker is…” Before Rex could finish, another Imperial Gunship touched down upon Onderon’s surface.

Rex could sense who was in the Gunship, before the doors opened and out stepped Cyron Klask. “Klask? What happened to Vader!?” Klask slowly walked towards Rex and Ahsoka, as he unclipped his Lightsabers from his belt, but didn’t ignite them.

“Vader’s currently digging himself out of a mine shaft at the moment. Anyway, I came to you because I have learned that someone close to me lives and I want to change. I’m looking for ideas on how to change the Kyber Crystals in my Lightsabers…”

For a moment, Ahsoka stood there, confused, not knowing who Klask really was. “Rex, who is this?” Rex was about to say something to Ahsoka, when Cyron introduced himself for Rex. “My name is Cyron Klask. I was a Jedi survivor of Order 66 and was plagued by the Dark Side for so long that I couldn’t even see that someone I cared for deeply survived the fate I thought they had suffered. Do you know how to purify a Lightsaber Crystal?”

Using the Force, Ahsoka opened two small hatches on Klask’s Lightsaber hilts and took the Kyber Crystals out of the two hilts. “Sit down, Cyron.” Ahsoka and Klask then sat down and closed their eyes, before Ahsoka closed her hands into fist, with the Crystals still sitting the palm of her hand.

While Ahsoka and Klask were meditating and purifying the Kyber Crystals, Rex sees two Senators talking inside the base: Senators Mon Mothma and Bail Organa. Rex slowly walked towards the two Senators, before Mon Mothma turned her head and saw Rex walking inside the base.

“Ah, Captain Rex. What brings you here to us at the moment?” Rex briefly turned his head to Ahsoka and Cyron outside the base, seeing that the process of healing the Kyber Crystals must’ve been successful, before he turned back to Mon Mothma. 

“I’ve been thinking about this for a while now, but…      may I join the Rebel Alliance to restore the Republic?”