Shmi Skywalker.
Darth Vader nearly choked on the name nearly every time he wanted to say the name.
Her name.
Looking back at it all, Vader felt a little guilty thinking about it.
She had sacrificed her life to give her son the life he deserved. A life free from the slavers and hardships on Tatooine. Granted, he didn't exactly enjoy all of the Jedi lifestyle (e.g. no marriage), but he was happier as a Jedi than a slave. And yet, he didn't sense a trace of regret or sadness in his mother. He knew that she had wanted him to be happy and happily gave her own happiness for her son's.
Whenever he said her name, he would magically transform back into Anakin Skywalker, even just for a little bit. He would look down in sadness as Anakin Skywalker and cry a single tear as Anakin Skywalker.
Toughened by the war and his training as a Sith, he had a few weak spots.
They were Padme, his beloved wife whom he wrongfully murdered. His unborn child, whom he felt great remorse for. And his deceased mother. These are all the people who could strike a tear from the supposedly mighty Darth Vader.
It had been a while since he had paid his mother's grave a visit, so he decided to go now since he couldn't see why not.
His Master, Darth Sidious, or more well known as Emperor Palpatine, never denied Vader if he ever wanted to go someplace to prevent weakening their bond.
"Yes, of course. Someone will prepare your flight right away, Lord Vader. Would you like company? Because a couple of the Stormtroopers can accompany you to make sure everyone is in line, but of course, you probably won't need their help." Vader shook his head.
"I will not need any assistance nor will I want any company. I will go there alone."
"Enjoy your visit Lord Vader."
With that, Darth Vader turned away, his black cape rustling from side to side with every footstep. He disappeared, leaving Palpatine with a dark expression on his face.