Demigra and codenamed Starkiller, was a male Makai apprentice of the Sith Lord Darth Vader. A powerful Force-user who lived during the era of the Galactic Empire and served as the Supreme Leader of the First Order approximately thirty years after the Battle of Endor , Demigra originated from the Wookiee home planet of Kashyyyk as the sole offspring of two Jedi Knights who deserted the Jedi Order during the Clone Wars. Following the death of his mother, the young Makai's father was killed in battle by Darth Vader. Though only a child, Demigra possessed an exceptionally strong connection to the Force that the Dark Lord of the Sith sought to exploit.

Thus, Darth Vader abducted Demigra in order to train the orphan in the ways of the Sith Order. Although the Sith were limited to only two members at any given time, Vader nonetheless trained Marek as a secret apprentice during his own apprenticeship to Darth Sidious, the Sith Lord who ruled the galaxy as Emperor Palpatine. The physical and psychological trauma of Vader's unforgiving training regimen resulted in Demigra's immersion within the dark side of the Force as his Master intended. With his childhood memories suppressed and his original identity forgotten, Demigra only knew himself as the Dark Lord's apprentice; a Sith assassin who operated under the codename "Starkiller" and a living weapon to be deployed against the enemies of Darth Vader.

In addition to the assassination of numerous targets that included Vader's many rivals, the apprentice trained for years in preparation for the day when he would be ready to aid his Master in a confrontation with Darth Sidious. This singular goal became Starkiller's obsession as he longed to become a true Sith Lord. The pinnacle of Starkiller's training saw him deployed against Jedi targets for the first time in his life in 3 BBY. With the death of the Jedi, Darth Vader declared that the time had come to execute their plan to overthrow the Emperor. Elated at the prospect of finally fulfilling his sole purpose in life, Starkiller rendezvoused with Vader on the Executor only to be betrayed and severely wounded by his Master who claimed that Sidious's spies had discovered the existence of the secret apprentice. Pressured by the Emperor, Vader demonstrated his loyalty by seemingly killing Starkiller. In truth, the betrayal was a ruse that allowed Vader to save his apprentice's life.

Upon Starkiller's full recovery in 2 BBY, he was outraged by the discovery that his Master was unwilling to challenge Darth Sidious with Starkiller's aid, a year later Demigra met a young Kaishin by the name of Chronoa, who would later gave birth to twins, he would later leave the Empire to work as an assassin. During the apprentice's infiltration of the second Death Star during the Battle of Endor, Demigra witnessed his former Master in battle, along with the Jedi Knight Mira, against the Emperor, after escaping the station's destruction, Demigra became obsessed with his Master's goal: the elimination of the Jedi.

During the years of the New Republic, Demigra founded the First Order, a political and military faction, that came into existence as a result of the fall of the Galactic Empire. In spite of its collapse the Empire's legacy survived in the Unknown Regions of the galaxy where former members of the Imperial Military plotted their return to power. Their cause would grow in support through some Imperial sympathizers who briefly inhabited a wing of Republic politics before abandoning the nascent democracy to join the Imperial-based movement in the Unknown Regions. Inspired by the fascist ideals of the Empire, this movement sought to be better and remove all weaknesses and flaws that the Empire had, ultimately resulting in the formation of the First Order.

When Demigra found out that he had two sons, one of which was the student of Mira who he despised, he would eventually try to convince his children to join them.