I'm not sure specifically as it could have a variety of characters. But it might include some new Jedi or Sith characters.
Since the 'Star Wars Visions Novel' is likely to be a collection of diverse stories, the main characters could be different in each one. There could be a young Padawan on a quest to discover a long - lost Jedi artifact. Or perhaps a bounty hunter who gets caught up in a struggle between the Rebels and the Empire. There may also be a Sith apprentice trying to prove themselves to their master. In short, the characters could range from the typical Star Wars archetypes like Jedi, Sith, and smugglers to completely new and original creations.