+HP/-Atk Ninian

Dancers can work with any team honestly. I have a -Attk/+HP Azura that I constantly use for various teams to begin with.

Yea, sucks she has -Attk, but thankfully the attack stat doesn't apply to allowing your ally to move another turn. God help us if it does.

You'll find a better Ninian down the line at some point and a dancer is vital to a lot of different team compositions. Having one in general is just useful to begin with.

Heck, Ninian dances and debuffs, so she's versatile regardless honestly.

Honestly, this Ninian is fine. She has pretty bad attack anyway, so the attack bane doesn't really hurt her. If you are using Ninian, you probably won't use her for damage anyway, thats Azura's job.
If I were you, I would use her. The only problem is going to be leveling her up. Bring 2 Dancers with hone spd and atk, and a healer, and unequip Ninians dance and you should be fine.

Same IVs as you my friend, honestly anything is fine as long as she's -atk, as her attack stat is pretty garbage even with a boon and isn't meant for any kind of combat anyway. Every other stat is important for her, defense is needed so it scales well with triangle adept to help her take less damage against sword units, same concept with res only against magic.

Those are great IVs for running Infantry Pulse or Panic Ploy.