Pokemon Conquest was a game that was way ahead of its time, this game featured a Pokemon world that was based in the past. The gameplay was very "Fire Emblem '' like with the tactical mechanics but using Pokemon instead of heroes. Pokemon Conquest was a great spin-off for Generation 5, however, we haven't gotten a sequel.
We have 2 regions that have very deep lore that we never got to explore much, I am talking about the Kalos region and the Galar region. Both these regions have Pokemon that would fit the esthetic of the past. Both regions have rich lore with their respected Box art legendary that could be dwelled on a bit more.
If Pokemon Conquest decided to go with the Kalos region we could potentially get to live the events that Pokemon X and Pokemon Y tells us about such as Az and his Floette, The ancient weapon, and even see the Legendary Pokemon in action. The idea that we could see a more primal, less tamed Kalos region would really shape the story of Pokemon X and Y. Some Pokemon could get origins of how they were created such as Honedge, Sylveon, Delphox, Greninja, and Chesnaught. Az has been confirmed to be 3000 years old so having him as your companion, Rival, villain or the main character himself would be very possible in a Conquest Sequel.
Pokemon Conquest being based in the Galar region would be my pick if I was the director of the game. Galar has a story with 2 heroes that went on to become kings and this story got very little attention, a Pokemon Conquest telling the story of these 2 kings would help close the lore gap by a lot. I feel like Pokemon Sword and Shield left us in the dark when it came to the story of the 2 kings that took place 3000 years before the current game. Pokemon Conquest could have the player playing as either the Sword Hero or the Shield Hero and explore the story that took place during the Darkest Day, I struggled a lot to understand the concept of the Darkest Day while playing Pokemon Sword and Shield and part of that was the poor storytelling. The Galar Region has Pokemon that would be great to see the origin or how they became how they are, Pokemon such as Corviknight. Galarian Meowth, Polteageist, Coalossal, Copperajah, Zacian, and Zamazenta could all benefit from a little bit of extra love and attention.
In conclusion, regardless of the direction Pokemon Conquest decides to go I will be excited to get my hands on it. I am hoping that Pokemon Legends: Arceus becomes a success because the aesthetic of a pokemon game in the past could ideally open the gates for a Pokemon Conquest game.