At first, Ahsoka has no idea that Anakin Skywalker and Darth Vader are one and the same. She discovers the truth in Star Wars Rebels when she encounters the Sith Lord in a space battle. What she senses is so shocking to her that she passes out.
In Rebels, she felt Anakin's presence when she tried to feel Vader through the Force. The overwhelming realization caused her to faint. Later, she fully realized and accepted Anakin was now Vader.
Summary. Ahsoka Tano believed Anakin Skywalker was dead after Order 66 because she couldn't sense his presence in the Force anymore. Ahsoka had seen Anakin flirt with the dark side before, but couldn't fathom that he would betray everyone.
Very few people knew that Darth Vader and Anakin Skywalker were the same person up to his death in 5 ABY. Imperials who knew in the current canon: Sidious (emperor), Grand Moff Tarkin, all or most of the Inquisitors, Grand Admiral Thrawn, various clones in the early empire.
Ahsoka Has Learned From Anakin Skywalker's Redemption
Despite his corruption and fall to the dark side with decades as Darth Vader, his son Luke was able to sense the good that had been buried, reaching out and refusing to give up on his father.
Tales of the Jedi raises an interesting question about Darth Vader's morality and motivations during the rise of the Empire, suggesting he knew of Ahsoka Tano's survival after Order 66 but kept it hidden from the Empire.
After the Clone Wars and Order 66, Darth Vader always knew his former apprentice Ahsoka Tano was alive and that he would one day face her in battle - long before it happened in Star Wars Rebels. Ahsoka Tano unwittingly played a crucial role in Anakin Skywalker's fall to the dark side.
And while his warnings don't work, at the very least, it shows that Maul became aware of Anakin and what he would soon become. With the rise of the Empire, it's likely Maul caught on to Vader's existence pretty quickly.
Return of the Jedi establishes that Yoda was aware that Anakin Skywalker had fallen to the dark side and become Darth Vader. When questioned by Luke Skywalker, he confided that Anakin was Darth Vader. Later, Obi-Wan Kenobi's Force ghost confirmed that Anakin had indeed fallen to the dark side and become Darth Vader.
She certainly knew something. The “I know. More than you realize, I know” line makes that clear, as does the Forces of Destiny short with Anakin, Padme, and Ashoka.
While their duel on Malachor was interrupted before a victor could emerge, the damage sustained by the Sith Lord was evidence enough that Ahsoka could beat Darth Vader.
Summary. A disturbing theory suggests that Darth Vader kept one of Ahsoka Tano's lightsabers for a darker reason, potentially using its kyber crystal to improve his own blade.
R2-D2 was present when Padmé gave birth to Leia and Luke, so he knew Luke was Anakin's son – but what he didn't know was that Anakin became Darth Vader. In addition to that, Anakin's fall was surely a painful event in R2-D2's life, one that he definitely wouldn't like to remember or even talk about.
Leia's Force abilities and her lack of awareness of her true identity also contributed to Vader's inability to sense their familial connection. Vader's denial of Anakin Skywalker's legacy and his fear of getting hurt again prevented him from realizing the truth about his children until later in the original trilogy.
Darth Vader acts like he doesn't even know C-3PO or R2D2. They were with him since he was a child. He did everything he could to forget his past. Also, his plating had been replaced many times, and protocol droids all look very similar.
Darth Vader didn't learn he had a daughter until Return of the Jedi, when he stood before Emperor Palpatine. The Emperor's power probed Luke's mind, attempting to goad him to fall to the dark side, and he discovered Leia's existence. "Sister," the Emperor taunted.
Instead, the diminutive droid appears to have kept his own counsel, perhaps wary of interfering too much in Luke's personal journey. C-3PO lost those memories, but he remained with Han and Leia's family after Return of the Jedi, so can reasonably be assumed to have learned the truth by eavesdropping.
Yep. Darth Maul didn't really say or show straight up that he "feared" Darth Vader, but he openly stated his belief that he could not defeat Darth Vader without the help of the Jedi, therefore on his own.
Unfortunately, Rex and Vader never meet again though. Why didn't Palpatine feel afraid of showing his evil actions, behaviors and ways to Anakin and the Jedi anymore?
While the Star Wars canon doesn't explicitly confirm his regret, the intricacies of his relationship with Ahsoka and the remnants of his former identity could have stirred some degree of internal turmoil.
But before the battle for Coruscant, they had to split up and Rex went with Ahsoka to Mandalore, and Anakin went to Coruscant. After that, Anakin and Rex never saw each other again.
Yup. Anakin's vision of Padme's death is the main catalyst behind Anakin turning to the dark side. Ahsoka staying or leaving is irrelevant next to Anakin's unhealthy attachment to Padme.
