Vader learns that the famous Rebel pilot is named Luke Skywalker, and although he seems almost dismissive of the name, he sets a plan in motion that nearly has him clash with Luke in a lightsaber duel. Retroactively, Vader's reaction is fitting, since another Legends property adds to Darth Vader's discovery.
As such, Vader never considered being a father when he learned that Luke was alive. Instead, he only thought about using Luke to gain complete control over the entire galaxy by overthrowing Palpatine.
What did Darth Vader feel after finding out that Luke is his son? He was pissed. Why didn't Darth Vader show much of his craziness or weirdness anymore? Well, like what happens to all great men, he grew up and got old.
He did know what Luke was his son, once he knew that Luke's last name was Skywalker. After Vader sensed the strength of the Force in Luke, he spent time trying to find the identity of the young Force-wielder who had destroyed the Death Star.
Vader didn't assume he was his son because there were plenty of people out there in the universe who could have been Force-sensitive. However, by the time the Battle of Hoth (ESB) had happened, Luke's name had spread all over the galaxy and the Emperor knew of it and told Vader.
In the post-2014 canon universe, the story that reveals Darth Vader discovering Luke Skywalker's identity (and thus the fact that the Death Star's destroyer is his son) is issue 6 of 2015's Star Wars comics by Marvel, which takes place sometime shortly after A New Hope.
During the iconic opening moments of Star Wars: A New Hope, Darth Vader has a tense confrontation with Princess Leia, an adversary who, unknown to him, is actually his daughter. Despite participating in Leia's interrogation, the Sith Lord doesn't uncover his familial connection with the rebellious royal.
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.
Alderaan's princess knew she had been adopted by Bail and Breha Organa after the Clone Wars, but she had no idea who her parents were. That was until Luke Skywalker told her the truth - that he was the son of Darth Vader, and that she was his sister.
The added risk Darth Vader takes in allowing children to live in a situation where he could have killed them proves that he regrets killing Younglings and will avoid harming any more children for the rest of his days, though intense intimidation is a dark strategy to avoid repeating his Youngling massacre.
The short answer is yes, without a doubt, Vader regretted becoming a cybernetic monstrosity. First, there's the constant pain and discomfort from his suit. Worse, however, is the psychological pain. Vader destroyed everything he had ever known for a chance to save Padme.
In The Phantom Menace, when Qui-Gon Jinn meets tiny Anakin Skywalker and his mother, he goes on about how the Force is like, crazy strong with Anakin or whatever, and then asks his mother about Anakin's dad. Shmi Skywalker is pretty clear in her answer: There isn't a father. She was impregnated by the Force.
The space station was destroyed, but Vader survived, and he flew into the far reaches of space. After the destruction of the Death Star, Darth Vader became obsessed with finding Luke Skywalker, who he discovered was his son.
He wasn't supposed to kill Luke; he wasn't even supposed to beat Luke. Vader's only goal in the fight was to make Luke lose control of his emotions and bring him closer to the dark side -- and that's exactly what happened. Vader had to obey his master, so he goaded Luke until he touched the dark side.
Despite Vader's seeming loyalty to the Emperor, Palpatine wanted to replace his servant with a new apprentice, while Vader plotted to overthrow the Emperor so he could rule the galaxy with his son. In the end, Luke surrendered himself to Vader on the forest moon of Endor.
Has Leia 'forgiven' Anakin Skywalker for his crimes as Vader? Yes, in the “Legends” part, she even named her third child for him, as a symbol of his heritage and redemption. However, it's more than acceptance that Anakin is her BIOLOGICAL father and she got her personality and Force sensitivity from him.
Although we never see Leia fully reconcile with the fact that Darth Vader is her father, it's worth noting she did actually forgive and accept the former Sith Lord in the non-canon Legends novel "Tatooine Ghost," by Troy Denning.
She figured out her mother's identity after Return of the Jedi, when she learned she was the daughter of Anakin Skywalker; it didn't take Leia long to connect the dots between Anakin and the senator of Naboo he had spent so much time with during the Clone Wars, who died under mysterious circumstances on the day Leia ...
She also knows Obi-Wan, and she knows him well. Her holographic plea for help, already iconic, will never be the same. She knows Obi-Wan's real name as well as his alias of “Ben.” When Luke comes barging into her cell and says, “I'm here with Ben Kenobi,” Leia jumps off the bunk in an instant.
Leia became famous for mercy missions undertaken aboard the Tantive IV, but the Empire suspected her altruistic acts were cover for treasonous activities. After the Tantive IV intercepted rebel transmissions of the Death Star plans at Scarif, Darth Vader captured the blockade runner above Tatooine.
Yoda. Yoda's knowledge of Luke Skywalker's true parentage was also confirmed in Return of the Jedi. As with Obi-Wan, Yoda believed that Anakin's fall to the dark side made him unsalvageable, with the Darth Vader persona being his only identity following his ascension to Sith Lordship.
A Skywalker by blood, Leia Organa is known to be Force sensitive. Is she showing those abilities in the new Star Wars miniseries? "I am inside your mind." These are the first words that the phony Jedi Haja Estree speaks in the second episode of Obi-Wan Kenobi, pretending to read the thoughts of a customer he's conning.