Darth Adnihilo

Darth Adnihilo, who previously went by his original name Jason Archwalker, was a Human Male Correlian Sith Lord born on Correlia in 26 BBY. Jason Archwalker, who was twelve, was discovered to be Force-sensitive by Darth Estus, and for ten years Darth Estus trained him everything that he knew in the ways of the Dark Side of the Force. After Darth Adnihilo betrayed and murder his Sith master, he traveled to Coruscant in search of the legendary Dark Lord of the Sith Darth Sidious.

Darth Adnihilo later helped Darth Sidious orchestrate the war with the Rebellion in order to wipe out the Rebellion. When Darth Sidious' spirit was annihilated in 11 ABY, Adnihilo took it upon himself to find and train Force-sensitive beings to be adept in the Dark Side of the Force in order to take back control of the New Republic. Adnihilo later fought along side with his Sith minions in the Yuuzhan Vong War and the starwars:Swarm War. After the Swarm War, Darth Adnihilo, who was wounded during a battle with a Jedi Knight, traveled back to Coruscant and found documents that Darth Sidious had kept which told how a Force-sensitive being could sustain his or her life.

Early Life
In 26 BBY, Jason Archwalker was born on the Capitol Planet of the Correlian System called Correlia. Jason, twelve years of age, remembered very little of his parents, and instead of growing up like a respectable Correlian civilian, Jason got into fights with local gangs and was nearly killed when he was saved by a cloaked person who revealed himself as Darth Estus. The Sith Lord sat beside Jason and told him that the Jedi were one of the groups that were behind the murder of Jason's parents. After hearing this, Jason cried inside himself while letting the anger and hate swell in himself. Darth Estus found that moment to seduce Jason. He told Jason to kneel before him. Jason did so without hesitation, and he was then named Darth Adnihilo which meant in the human tongue "Annihilate".

Behind the Scenes
I was inspired by the story of how Galen Marek was taken under Darth Vader's wing. The rest of the article is pure originality.