Can I please have my beloved Arendel back! I think a second scenario requiring the completion of this scenario would be great! Faeryl is accidentally revealed to her fellow rulers. She controls the heart of the Elven Nation by suggesting what they've discovered is false. As with everything, some don't believe her, but most stick with their wonderful (fake) Arendel.
Faeryl, perhaps mentally morphed by having to pretend to be Arendel, just doesn't want to kill her sister (which she could do), but needs to keep her sister buried to not be executed by her own empire. She doesn't even want to think of going into Exile.
The scenario, as won by Faeryl, would produce a Svartalfar victory. She would then be seen as Arendel and only needs to wait for everyone to forget before she goes about putting back into place the Svartalfar ways. A twist could be that if you play as Faeryl, you have the Ljosalfar civilization trait instead of the Svartalfar civilization trait. Or both! As those who hold onto the prospect that what Amelanchier and Thessa have discovered, they flee to (fake) Arendel's Ljosalfar nation. Also, If you play as Faeryl, you'll see yourself as Ljosalfar!
As played by Amelanchier or Thessa, you see Faeryl's nation as Svartelfar. Faeryl still has the civilization traits of both the elven nations. You, as a Ljosalfar, only work with the Ljosalfar trait.
This is some of the best stuff. When you pick leaders, you pick Faeryl, Amelanchier, or Thessa. If you pick Faeryl, you see yourself as Faeryl. Amelanchier and Thessa, pretty sure of themselves, call you Faeryl. If you pick Amelanchier or Thessa, you would see Faeryl as Arendel who is pretty sure she's Arendel. But you're pretty sure she's not. (If you're Amelanchier, you're pretty sure she's hot

)
I don't know if I have to point this out, but the obvious conflict is a civil war... not reignited, though, because this one is under slightly different pretentions.