No, Rey's father, Dathan, wasn't a Sith, but he was a failed, non-Force-sensitive clone of Darth Sidious (Emperor Palpatine) created by the Sith Eternal to potentially house the Emperor's spirit or continue his bloodline, making him technically of Sith lineage but not a practitioner. He escaped, married, and had Rey, who inherited Palpatine's strong Force connection, prompting the Sith to hunt them to use Rey for their plans.
Rey's father, Dathan, was not Palpatine's son in the traditional sense but rather a clone derived from his genetic material. Designed to be a vessel for the Emperor's essence, Dathan lacked the Force potential necessary to carry out this purpose.
No, Darth Plagueis is not Anakin Skywalker's father; Anakin had no biological father, being born of the Force itself in response to Plagueis's dark side manipulations, with Palpatine's tales of Plagueis's power over life being a manipulation to turn Anakin to the dark side, though Plagueis's attempts to create life did inadvertently cause Anakin's conception.
Abrams, director of The Force Awakens and The Rise of Skywalker, hinted the revelation that Palpatine was Rey's grandfather in the ninth installment was an early idea when working on the seventh chapter.
Palpatine Saw Rey As A Tool, Not A Granddaughter
Kylo Ren idolized his grandfather Darth Vader, but Rey never saw Palpatine in this way, never even acknowledging her familial connection to The Emperor as anything beyond a genetic technicality. For his part, Palpatine didn't really think of Rey as family either.
Though there was some debate among the fans that Anakin Skywalker's son, Luke Skywalker, was actually the Chosen One since he caused his father to destroy Darth Sidious, the debate was settled when George Lucas himself confirmed in an interview that Anakin, even after becoming Darth Vader, was still officially the ...
"Not from a Jedi." Sidious remembered Plagueis as a powerful Sith who discovered the ability to achieve immortality.
Likely unaware of his true nature, Snoke was an artificial genetic strandcast created on the planet Exegol by the resurgent Dark Lord of the Sith and Galactic Emperor Darth Sidious as a proxy and the product of cloning experiments.
It's pretty clear that operation necromancer is the effort to bring back Emperor Palpatine and Snoke is a step in that effort who served as an intermediate vessel to host his spirit until the Palpatine clone was ready. It's the project to clone palpatine in to a new body after his death in VI.
Palpy was stronger with the force, absolutely. But Yoda was the better duelist. Hence why he forced a sword fight vs a force fight. It could have gone either way depending on the circumstances, but the fact that Palpy kept keeping distance is the only reason he won.
Luke was the last Jedi, then. Rey is the last Jedi, now. The title of each film in the sequel trilogy is a direct reference to the main protagonist of the sequel trilogy, Rey. In the Force awakens, it awakens in her.
The two embraced and shared a kiss as Solo peacefully vanished in Rey's arms. Although Solo was the last of the Skywalker bloodline, Rey assumed the name "Skywalker" to honor their memory and in recognition of her chosen family. Sometime later, the now self-proclaimed Rey Skywalker became a Jedi Master.
In The Rise of Skywalker (2019), the final film in the sequel trilogy, a resurrected Palpatine is revealed to be the grandfather of Rey, a Jedi-in-training who is the protagonist of the sequel trilogy.
Darth is a title for a Sith Lord. There have been more than one Darth, but only one was named Vader.
Darth Maul is the weakest. Bane was strong : he killed all the Sith and lots of Jedi.
Dooku voluntarily left the light side behind and became Darth Sidious' dark side disciple, taking the secret name Darth Tyranus and leading the Separatist army.
Anakin Skywalker, once the prophesied Chosen One, fell to the dark side through fear, pride, loss, and manipulation. His bond with Padmé, mistrust of the Jedi Council, and belief in Palpatine's promises led to his tragic transformation into Darth Vader.
Voldemort chose Harry instead of Neville because he believed that purebloods aren't as powerful as they claimed to be. He was a half-blood and he was stronger than everyone around him and he knew that Harry would be the one with more power.
In the opera scene, he talks about how Darth Plagueis could manipulate the midichlorians to produce life, insinuating that the sith lords created Anakin. Clearly by this point Palpatine is well aware that Anakin is the chosen one.