The five heroes are equally this story’s protagonist, but Barak is the one who initiates the call to adventure, beginning his journey across the continent. If Barak does not exist, then no one notices the Void affecting the southern farmlands, and so no young wizard goes stumbling into the Children of the Stars’ forest.

Malka would likely just keep walking north through the forest, uninterrupted and directionless. She’d find adventure out there, certainly, and would probably get herself into too much trouble with no one to back her up. I doubt she’d survive well. It’s possible she would come across Shiri anyway, but Malka would not ask Shiri to leave the forest. Either way, Shiri stays home with her people, never learning to care about the outside world.

Paz and Lior would still meet, and Paz would still break them both out of jail, and Lior would still save Paz’s life on the road. There would be no Purim tavern brawl without Malka, and so no new friends found there. Paz and Lior would travel together, eventually learning of each other’s pasts. Paz may make a significant sacrifice to break Lior’s curse - an oath of solitude, perhaps - or she might find the price too much to pay. Lior would not believe it to be possible to destroy the Void, and so would not suggest that they try.

A mayor would be murdered. A gryphon and its child would be captured by poachers. A plague would decimate a small town.

The Void would continue its northward spread, consuming more and more of Besh. Without a Child of the Stars around, no one would realize that it can be stopped. People would die; people would flee. Maybe, when it reached the forest, the Children of the Stars would stop it. Or maybe they would not realize it was coming until it was too late. Maybe the world would end.