Palpatine easily manipulated Anakin even when Ahsoka was part of the Jedi, so it's likely nothing would've changed if she hadn't left them. She would, however, have been another obstacle for the Sith, requiring a careful and deliberate plan to separate her from her master.
Years later, when Ahsoka learns of her master's transformation into Darth Vader on Rebels, she partially blames herself for Anakin's turn to the dark side and holds some regret for leaving him and the Order behind.
Instead of Anakin learning to let go of Ahsoka, she instead attempted to let go of him and her attachment to the Jedi. Anakin was disappointed that Ahsoka chose to leave, feeling as though she was his failure.
Would Anakin have turned if Ahsoka stayed on Reddit?
Yes Anakin would turn to the dark side even with Ahsoka, and likely would have killed her anyway if she was realized in Episode 3. The guy burnt through the entire Jedi Order, Mace Windu, and nearly kills Obi Wan before falling to his ego.
Though she loved Anakin, she needed to find herself "without the Jedi...and without you." Anakin was still loyal to the Republic, more specifically to its leader Palpatine, his surrogate father and mentor, and couldn't leave his wife Padmé for his student, so he stayed, but she left.
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.
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.
Ahsoka's departure haunted Yoda for some time afterward; he felt extremely guilty and remorseful, partly for refusing to stand by her and partly for placing her on the path that led to her departure from the Jedi Order. In fact, his guilt was so great that the Dark Side attempted to use it against him, but failed.
She was my friend. Ahsoka and Padmé Amidala. Ahsoka and Padmé greatly respected and admired each other. It was Padmé who taught Ahsoka that politics, as well as other things, aren't as black and white as she once thought.
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.
Desperate to clear her name, Ahsoka was captured, stripped of her Padawan status, and expelled from the Jedi Order. Her Master Anakin Skywalker, however, never stopped believing in his apprentice's innocence and uncovered the truth: Jedi Barriss Offee, Ahsoka's friend, was the real culprit.
Yoda knew about Ezra and Ahsoka, and I don't think that someone as linked to the Force as he is would assume them to be dead. But we don't know where Ezra is, and we've seen him fail against fighting Vader.
Though it wasn't a romantic love, there was a familial love that Ahsoka (Dawson) felt for Anakin (Christensen), which makes his fall to the dark side and becoming Darth Vader all the more difficult for her in later years.
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.
How did Darth Vader feel when he found Ahsoka's lightsaber?
Darth Vader was probably confused. Last thing Vader saw was Ahsoka being pulled from his lightsaber strike before he fell into the chasm. So he didn't land the killing blow and was probably intrigued by what happened. Even if he did kill her, remorse would unlikely be the emotion to kick in.
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.
Ahsoka would have been the perfect confidant for Anakin, not Palpatine, and she would have taken Anakin's fears seriously. It's even possible Anakin would have assigned his Padawan to protect Padmé and their unborn children since he couldn't always be there.
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. Snips has her suspicions confirmed when she comes face to face with Vader in the Rebels season 2 finale, in a Sith Temple on the planet Malachor.
In this timeline, Anakin would no doubt have become one of the most respected and powerful Jedi Masters on the council, joining the likes of Obi-Wan Kenobi, Mace Windu, and Yoda. However, Anakin's relationship with Senator Padmé Amidala would stand as a potential roadblock for the newly appointed master's Jedi career.
Skywalker presents Tano with her lightsabers, which now shine blue. While the lightsabers were in the custody of the Jedi, Skywalker took care of them, taking the opportunity to, as he saw it, "improve" them. The blades changed color to blue as a result.
All things considered, it seems as though Ahsoka intentionally made the decision to not use both her lightsabers likely because the shorter shoto wouldn't have been as effective. An extended duel with Marrok and his fully ignited lightsaber likely necessitated Ahsoka to change tactics.
How does Anakin have a Padawan if he's not a master?
Because Jedi don't need to be Masters in order to take and train a padawan. Obi-wan took Anakin as his padawan literally right after he'd graduated from padawan to knight. So therefore, you can train others to be Jedi as a Jedi knight. It helps towards the experience in becoming a master but isn't necessary.
