For the past week or so I've been turning over the idea of a Fate game in the strategy RPG in my mind, sparked by the recent announcement of the new Fire Emblem game. I'm very certain I'm not the first person to think of this idea and I won't pretend like I am, but it's one I haven't been able to let go of and I think it would be at least a great one-off diversion for the franchise to experiment with.
Fate is predisposed to creating large casts of colorful characters in the same vein as Fire Emblem and its genre-mates. The El-Melloi students, for example. Our most recent video game even shared a specially-requested writing team with Fire Emblem Three Houses, a connection that I can palpably feel as a fan of both.
To have this make the most sense, I would imagine it'd have it's own Holy Grail War setting with a new cast of Masters and Servants, though maybe with a few familiar faces sprinkled in in typical Type-Moon fashion. Masters and other Mages would fill the role of the rank-and-file characters you pick up along the game, while Servants would be the stronger characters with unique weapons and skills (think the FE Lord, like Marth or Ike). Say, for example, you started out as a rag-tag group of Mages who agree to work together for the Grail War, either out of friendship or for another reason. You could recruit more by paying them off, helping them out, etc. Mages would have their own abilities too, tailored to their characters and particular styles of Magecraft. Mystic Code weapons could also be included to keep that feel of inventory management. A traditional class system probably wouldn't work, but it could be tailored to the characters instead.
An emphasis could be placed on Servants with Reality Marble or other terrain-altering abilities to create unique maps. Our existing Servants like Vlad or Zhou Yu, or some new ones, say Nimrod with the Tower of Babel or Khaemweset with some sort of Egyptian construction ability. Hub world exploration could also be utilized to highlight the day-night contrast often featured in Fate stories, with both feeding into each other. New Servants could be acquired by recruiting their Masters, taking them from defeated Masters, or forming bonds with Rogues a la Samurai Remnant.
I know the genre isn't for everyone, but frankly I doubt there's any Fate fan who's into every single entry already. I think this idea has a lot of legs and while I doubt it'd ever happen, it's probably going to be bouncing around in my head till the end of time. I'd love to hear other people's opinions on the idea.