If you can spend the dew, I'd giver her her new lance and refine, the Dauntless Lance. It'll keep the slaying effect, but give a lot of extra skills that are really good, plus it's refinement gives you both speed and defense when attacked, which is really good. Otherwise she looks pretty great. You could also swap her C skill for something like Atk/Def Bond or Atk/Spd Bond, since she doesn't have distant counter so DD3 isn't terribly useful on her. You may also wish to swap out Threaten Def for Atk Smoke (it's personal preference, you could go either way tbh) if you find her tanking multiple enemies. +7 effective defense is pretty stellar. Once February rolls around they'll make the first merge get rid of her bane, so she won't be -Def anymore, which will be pretty awesome. Hope that helped!