My idea for Rafiel's transportation was actually less "something else did it", and more despite his exhaustion and injuries, he was able to fly that far out of adrenaline and fear, but in the process ruined his wings completely. (And didn't remember because of a fugue state, something like that.) But that has basically no basis in canon, probably, and might be outright contradicted somewhere.

The only-royals-survived aspect of the herons was always really odd to me. It just seemed so unlikely, I guess, and there's no logical explanation for it. If there was some divine protection over them, it didn't exactly serve Lillia well -- and isn't there something saying there were other siblings too, or am I misremembering that?

I mean, miraculous survivals of only a select few magic royals is standard for FE, but that just seemed like an especially bizarre case to me.