Jeanne d'Arc Alter (ジャンヌ・ダルク・オルタ?), Class Name Avenger (アヴェンジャー, Avenjā?), is an Avenger-class Servant summoned by Ritsuka Fujimaru in the Grand Orders of Fate/Grand Order. She is also a boss-only character under the Ruler-class during the events of the Orleans Singularity.

Known as Jeanne Alter (ジャンヌ・オルタ, Jan'nu Oruta?), 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.

Since the proper Jeanne is not a hero, but a saint, the possibility of "summoning a different aspect of her" is nil. Because this black Jeanne has Gilles de Rais' anger... the prejudices and wishes for her to be like that... mixed in with her fundamental parts, a "side" that should never happen ended up being brought to the surface. As such, one can think that this Jeanne d'Arc is mostly made up by Gilles de Rais' prejudices; an existence encapsulating much of the corrupted Gilles' biases and feelings. The Dragon Witch that resurrected for the sake of getting vengeance against France. A holy woman who talks about justice as if she owned the place and, without having any doubts about that, is spurred on by the wrath against the people; that is the form which Gilles de Rais wished her to be like.