Apparently, Star Wars Rebels nearly saw the TV debut of Star Wars: The Force Unleashed lead Starkiller. After three storied seasons that definitely added a new dynamic to the space opera mythos, the Disney XD series is looking to close out with a huge bang as it treads the events leading up to the start of Rogue One: A Star Wars Story. Season 4 is shaping up to be jam-packed with several existing mysteries waiting to be resolved. That said, it is still great to look back and mull over the what-ifs of the show, including one that could have added Galen Marek as another threat to the Ghost Crew.
Starkiller was Darth Vader's secret Sith apprentice in The Force Unleashed video game. The character had a parallel story with his master. Dispatched by the Dark Lord to track and kill Jedis who survived the purge, his journey gave him multiple opportunities to come back to the light and be a hero instead of an antagonist.
Witwer, a veteran Star Wars voice talent has voiced both Maul and Emperor Palpatine/Darth Sidious in numerous projects, has revealed during his Twitch stream event (via Comicbook.com) that Starkiller was at one point being mulled over as a potential Inquisitor:
“Dave did share with me, by the way, he considered making Starkiller an Inquisitor in Star Wars Rebels,” Witwer said. “It didn’t quite fit the story that they were telling, but he did think about it because he thought that would be interesting.”
The Inquisitors -- who had a similar role to Starkiller, was a group of Force-sensitives whose job was to make sure that no Jedis and other Force-sensitive creatures were left alive. They were recurring characters in the first two seasons of Rebels until the last met their end in Malachor during the season 2 finale 'Twilight of the Apprentice'. One has to wonder whether Filoni planned to incorporate Marek the way that he was depicted in The Force Unleashed. Rebels have previously used this trajectory with Agent Kallus -- originally an Imperial officer turned Rebel fighter.
While it would have been treat to see Starkiller officially make the jump to the extended universe canon, it is great that the franchise explores new material already. In its run, it has been able to find the balance between old and new, making the mythos more diverse and detailed. That said, it wouldn't be inconceivable to see the Sith apprentice appear in future animated series, novels or maybe event a live-action film. If anything, LucasFilm is carefully picking ideas and characters from its storied Legends' catalog to bring to audiences.