The Last of Us Part II Remastered expands the experience of the original PlayStation 4 release with a couple of extra play modes. Among them is the No Return Mode, a roguelike take on the game's formula, complete with multiple characters with different abilities and playstyles that make this mode quite fun.
At the very start of your No Return adventure, however, you will only be able to pick Ellie or Abby. Every other character has to be unlocked by completing certain tasks.
To unlock both Ellie-aligned and Abby-aligned characters, you will have to complete a set number of Encounters with specific characters. Encounters are the single combat scenarios picked from the board at the hideout, so you won't need to complete runs to unlock additional characters. In case you don't particularly like a certain character's playstyle in The Last of Us Part II Remastered No Return Mode, you can simply clear the required number of Encounters to unlock a character and then quit your run.