One of the common time periods I’ve seen people asking for is medieval Europe. There are pros and cons to this, but I was giving thiugh about what kind of game it would be. I think a combination of Odyssey and Unity would be the best.

You have the conquest battles of Odyssey, along with the rpg and open choices aspect. A similar concept to the Cult of Kosmos where you find clues to their identities and have to find them, hunt them, etc.

From Unity I would like to see the assassination missions back. In medieval Europe castles were where most nobles lived, and therefore would be where most of your targets would be. But I feel like you couldn’t just climb the walls and sneak inside like we do forts. Instead we have to create our own opportunities to get inside.

Not all assassinations would be this way, maybe just the “Sages” (or whatever equivalent) and some of the people from the main story. Maybe a noble would be hard to kill in his castle but if you invade his land, and draw him out into a battle and kill him there. Maybe you can choose to poison his food, and a servant takes it to him as a unique assassination.

The game could reward you for gaining more information instead of just running up the castle walls and killing everyone inside. There could be consequences for doing that, like the region becomes unstable and lots of people become hostile because their was a mass murder at the castle.

As for the main character, you could be trying to bring the assassins order up from shambles after the plague, you have a small castle and as you do assassinations and progress through the story, you spend money on upgrades to the castle, recruit people to defend it, upgrade the guards, like the ship from odyssey/black flag, and enemies can attack your castle which you have to defend.

These are just basic ideas and I welcome any criticism. I think the medieval period is unique and needs a unique gameplay style as well.