Hmm, missables... The only really dumb missable is a character in chapter 15, who requires you step on a particular square with one of two particular characters for him to even appear. And he's worth it, so yeah. Till then, your previous Fire Emblem experience should prevent you from missing out on much!
On the magic system, there's the magic triangle, but also Fire beats land beasts, wind beats flying beasts/falcon knights, and thunder beats dragons/dragon riders. Fire has the highest base power, wind has the highest accuracy, and thunder has the highest crit.
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"Duel audio? You mean like rap battles?" - termina_rzident
KrahenProphet and Kana are on opposite ends of the Awesome Spectrum.