Jeanne D'Arc (Fate) in her Third Ascension outfit from Fate/Grand Order. Her usual clothes become white, and she lets her hair down instead of wearing it in a braid. The hems of her gloves and thighhighs have fur trim added to them as well.
It looks similar to Jeanne D'Arc Alter (Avenger) (Fate)'s Third Ascension outfit, but that one is colored black and has some slight differences to the dress.