The protagonist is such a character in literature that cannot survive alone. They need support and guidance. The confidant character serves as the protagonist's closest companion, or they can be best friends and often a mentor in a work of fiction. They can occasionally be exchanged for the deuteragonist. When the main character or hero needs assistance or guidance, they reach out to this individual.
Examples - Horatio from Hamlet, Dumbledore from Harry Potter, and Gale from The Hunger Games