Fae Weapon Choices

Lightning Breath makes Fae a very reliable mage counter, especially with +res. Only red mages with an insane amount of fire power will be able to put a serious dent in her, aside from the obvious Naga tome of course. With weapon refine, most mages won't live against her, but I'm a bit biased since I have Lightning Breath+ on all my dragons. I feel like that's the best weapon for them.

Yes, especially if you are having Fae be a blue tome counter. Innate distant counter on a weapon is always good, doubly so with dragons and breath refinement.

I wouldn’t sacrifice the Nowi but lightning breath is good on Fae. For me, I managed to get a lot of adult Tikis and gave all my dragons Lightning breath via her

Nowis for merges are a touch too valuable to fodder. 5 star an adult Tiki when you have the feathers for it to fodder for Fae. Then pick either +Def or +Res refinement. If you build Fae right, she can tank and kill both Rein and Brave Lyn on one enemy phase. Seriously useful for arena assault.

Nowi isn't the best choice of fodder for Lightning Breath, but Fae definitely wants it. All dragons do except maybe Ninian and Corrin. Ninian because she has Atk far too low to do much of anything, and Corrin can use it, but can also use Dark Breath to be an awesome debuffer.