Long story short, after I recently managed to 1CC PoFV on every difficulty with every character, I remembered that Merlin and Lunasa didn't get their own Story modes, and I'm sure some people were disappointed by that (including myself), so I decided to make a mod that would allow you to play through the Story mode as them (beating every character in Match mode as Merlin and Lunasa is a challenge on its own, but is also quite a different experience, compared to the Story mode). You can also now encounter Merlin or Lunasa while playing through other characters' Story modes, too!
This mod uses a separate .dat and .exe files with Merlin and Lunasa replacing Lyrica's character slot, so you could play as them in the Story mode.
Still, this mod uses the same score.dat file as the original game, so I recommend installing this mod on a copy of your game, just in case.
GameplayDownload