+Spd/-Def is clearly the best iv, you can run an offensive BladeTome set on her. LnD with Desperation and she will destroy everything, a set with out BladeTome is also good aswel.
Honestly, her default skills are pretty good. You can change her B skill to Desperation if you have a *reliable* way to get her to low HP, or give her something like Drive Spd, but other than that her base kit is pretty much okay.
Ty you guys for the quick response! I'll definitely use the Speed one and play around with those builds. Best thing is they don't get in the way of each other either.
Pokemon GO
Fire Emblem Heroes
Fate Grand Order
Dragonball Legends
Dragalia Lost
IV Calc
Heroes