+atk -hp Nowi

That is arguably her best IV... build her now.

I have the same Nowi as you. Right now she has Fury+Swordbreaker, but the thing is that Nowi can kill most of the red swords in one hit, making Swordbreaker obsolete (except armored units). Once I get B!Ike, I plan to change her build entirely with Steady Breath, QR, and Bonfire. She also works wonders with the Distant Def 3 Seal as it allows her to tank Reinhardt and counter with a charged Bonfire.