I have this idea that Obi-Wan and Anakin being the last of the jedi and the sith, and probably being a Force Dyad, the Force would make them immortal to keep balancing the light and dark side. Now, wouldn't it be tragic? Knowing that cybernetic modification was an invasive procedure and that Vader is in constant pain, it would literally be hell for him. Actually-
A long, long time ago, Darth Vader killed Darth Sidious and took his place on the throne. In this story, he never met Leia, nor Luke. The rebellion eventually stopped existing because Vader was a good Emperor. For decades, centuries, he ruled. Still merciless and feared, he kept peace and balance in the galaxy.
Immortal but tired. His soul turned weaker and weaker. His mind too. Pain and time drove Vader mad and paranoid; forgetful. Every day was worst than the one before. Soon, he wouldn't know who he was.
Feeling some kind of end coming, he didn't want to be forgotten. He called for storytellers across the galaxy, asked them to tell his story. Hélas, each time, he felt betrayed. The story they told weren't his. Surely, they were changing the narrative. Being old and insane, he couldn't himself bring anything to his own tale. So he killed them all.
They all started running away, afraid to be chosen for the task. He sent for them all, the most known names, the most ancient scribes, the most talented singers and educated scholars-
Nothing soothed the ache of loneliness and despair that settled in his core when they got to work. None of them would satisfy his craving. As time passed, madness took him over and he could only remember this desperate quest. Gradually, everyone in the castle fled away.
Until one day, when an old and humble man came to his castle; no fear in his heart and infinite sadness leaking from him in the force despite his shields.
Although his voice were the loveliest sound he had heard in centuries, his songs were not about Darth Vader, the sith Emperor. They were about love and war, about longing and loneliness, about two brothers, about a first love, about sand and lava-
Vader let him finish all of his songs.
He always asked for more and-
The unthinkable happened.
Darth Vader learnt patience.
He accepted it when his storyteller said, every night,
"Tomorrow, you will have one more song. Only then."
Everyday, Vader would listen to the singer; entranced and strangely relieved. The old man became his only friend.
And Darth Vader fell in love with his old master all over again; unknowingly.
Got inspired by Three Thousand Years of Longing (the story about the prince and the old man) and the Hadestown's "epic III" which is an ancient melody about how Hades felt in love with Persephone.
"And what has become of the heart of that man now that the man is King? What has become of the heart of that man now that he has everything? The more he has, the more he holds, the greater the weight of the world on his shoulders. See how he labors beneath that load, afraid to look up, and afraid to let go. So he keeps his head low, he keeps his back bending. He′s grown so afraid that he'll lose what he owns... But what he doesn′t know is that what he's defending Is already gone."