Palla

Hmm, it seems fine ish. I'd change her sword for a slaying sword but otherwise not bad.

This is a minus speed Palla. While the build can work, I'd recommend getting one that's either neutral in speed or with a speed boon.

I'd personally change her sword. Gem weapons are good for Arena Assault, but for general usage it's pretty meh. Maybe something like Slaying Edge or Wo Dao.

Fury is a nice option for what you're going for, which is a Desperation build. If you have the resources, you could look into other speed skills like Brazen Atk Spd. Her defense and HP are fairly decent, so she can take a hit or two.

The seal, if she wasn't minus speed and you had someone with Hone Fliers, should be changed as well. Something to increase either her attack or speed.

That...works, ish, but I don't agree with it for a number of reasons
- She can build to be quite tanky, which means desperation would not be needed and she can use the special charge from the counterattack to get something more powerful going. Also means that fury is not the preferred A-skill because she won't like the recoil. Maybe something like brazen def/res?
- She has 30-ish spd on a neutral IV, right? With flier buffs she should be able to get at least into the upper 30s, which means brash assault shouldn't be necessary.
- Definitely switch out the weapon for something refinable. She's doing fine against greens; it's vs reds and vs blues that she will need more power, and the extra stats will definitely help. Slaying edge if you want one-round bonfire, maybe wo dao if you're more patient and want to really stick it to someone with an ignis.

I was thinking more something like this

As others have said I would reccomend changing a few things on her build. Here's my Palla build, she's neutral for IV's and has a fairly cheap build. I find that moonbow + Wo dao+ allows her to blast through most things and sword breaker allows her to beat just about any sword unit. Panic ploy for the seal works great since Palla has a ton of hp, mine is also paired with L!Robin so during earth season she hits 50 hp and 40 speed.

You, my friend, have an enemy phase iv unit, which means you need to set her up to get hit first. With speed like that she's in need of a way to double. I'd go for a QR bait unit with armor smasher so she can be aggressive toward tank units. If not guard then sword breaker so you can have the advantage on swords too. The sword breaker and QR have an HP threshold though. That's where brazen can come in and cover you. This can work well until you find a palla you think has better stat iv's