-Sprite (1,0) could use some fixing as there are some pixel errors with the dress.

-The swish sound on 5B, 2C and j.5B doesn't play simultaneously along with her grunt sounds.

-It would look nice if the opponent has palfx if they get hit by her ice attacks, Barrier and Luna Luna (The same could work with Akko with her Fire attacks, Sucy's smoke projectile and Shiny Arc).

-The Assist Select should be selected with the taunt button so you don't have to wait for the round 1 animation to appear and doesn't clutter the screen (And the Assist Ready sound effect plays once it's selected).

Now after comparing her with Akko, I noticed their super jump height when doing it upwards for both of them is exactly the same as the normal one. I think it should be slightly higher and add afterimages since it looks exactly the same as the normal jump aside from the sound effects. It should stay until they start falling to the ground or if Diana's Air Jump and Akko's Float.

Even though that frame was relatively quick, it's still kinda jarring as the tip of her hair is detached, the elbow of her right arm and 2 pixels of her left shoulder are missing. Hopefully Shim fixes it.

Speaking about 2C, the actual 2C sprites that use group 420 are unused and the current 2C is the exact same as the 66C. I think they should be different as the current 2C looks better as a rush down command than a move that trips the opponent.

Another method I can think of is to add an effect below their feet when they do it like in the MvC games. But it's not that high when jumping forward or backwards, that's why I compared it with PotS's characters since it's works somewhat similar and though of it that way so it doesn't look too identical to the normal one.

I changed 2C into a slide because it makes for a more interesting normal, both visually and functionally. Akko's 5C and 2C were like this, I wanted Diana to have at least one. The sprites being shared with 66C isn't an issue to me.

I think the most I would add is some kind of dust effect.