@Espurrhoodie started this idea, me, her, and @Nym threw ideas around. Basically, take the cast of Three Houses and give them personas that are past FE characters, or mirages if you want to say that. I made a list of my ideas, I decided to give everyone two. I used three rules:
1: They all have to be playable, so Edelgard can't have Arvis.
2: They have to be from different worlds, so Hubert can't have Henry and Tharja.
3: They can't already be used in TMS, so Hubert can't have Tharja even if his other was from elsewhere.
Some of these are less obvious choices than you'd think! Without further ado:
Rhea: Deghinsea, Emmeryn
Seteth: Nasir, Marcus
Flayn: Kurthnaga, Lissa
Gilbert: Tauroneo, Kellam
Shamir: Say'ri, Gerik
Cyril: Ross, Donnel
Jeritza: Zelgius, Lyon
Catherine: Titania, Hector
Alois: Brom, Dorcas
Byleth: Ike, Lyn
Anna: Awakening Anna, Heroes Anna
Dimitri: Ephraim, Skrimir
Dedue: Frederick, Mordecai
Ingrid: Marcia, Kent
Sylvain: Sain, Ranulf
Ashe: Rolf, Matthew
Felix: Navarre, Mia
Mercedes: Lucius, Gaius
Annette: Lute, Mist
Claude: Zihark, Heath
Hilda: Dwyer, Makalov
Lorenz: Bastian, L'arachel
Raphael: Stahl, Ilyana
Ignatz: Kagero, Forde
Marianne: Natasha, Delthea
Lysithea: Soren, Serra
Leonie: Kjelle, Tobin
Edelgard: Vaida, Mathilda
Hubert: Henry, Leo
Ferdinand: Eliwood, Geoffrey
Petra: Athena, Lethe
Caspar: Vaike, Kieran
Bernadetta: Neimi, Vika
Linhardt: Haar, Luthier
Dorothea: Azura, Micaiah
Yuri: Leon, Naesala
Constance: Elincia, Canas
Hapi: Boey, Nailah
Balthus: Joshua, Tibarn
I have bias towards games I've played and enjoyed of course...sorry Jugdral and FE6 and Archanea to a certain extent. Anna is there for luls. I want to point out Sylvain... "Cat! I'm a kitty cat! And I dance dance dance and I dance dance dance! Purrvocative posing!" Yeah, lol. Gatrie as his secondary would be too easy and obvious.
Enjoy, and what would your list look like?