Also known as Jeanne Alter, she is the Alter version of Jeanne d'Arc. Although designated an Alter, it does not mean that she is a different aspect of Jeanne d'Arc. A Jeanne of vengeance that Gilles de Rais, the French Army's marshal who grieved for Jeanne d'Arc's death, fabricated by means of the Holy Grail shortly after the execution of Jeanne in 1431. As a Heroic Spirit that is an exact opposite of the proper Jeanne, she is manifesting in the Avenger Class. In Fate/Samurai Remnant

Spoiler

Unlike the Jeanne Alter from Fate/Grand Order, Jeanne d'Arc herself transformed into an Altered state due to unique summoning circumstances that lead to her sacrificing her saintly purity.