One of my traditional FE "challenges" is a no reset run. Make a mistake? Deal with it. Someone dies? Carry on without. Lose your Lord? Playthrough failed.
I've also done what I think of as a prepromoted unit run, although that's not quite accurate; usually I also allow myself to use Thieves/Dancers/Lords as long as they aren't promoted. Note that in FE9, Laguz are also legit - they count as promoted units for experience purposes, after all.
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I don't like this duchy. Now, it's an adventurer.