All this talk about the benefits of straight vs. curved swords is
neat (and correct so far as I can tell). Since the eastern enemies
of the Lunars (Pentans and Heortlings) don't wear that heavy armor,
slashing weapons work well.
But, isn't the real reason that Yanafali use curved swords is that
Yanafal was cursed by Humakht for being Ressurected and can't use a
straight sword?