The actions of Gilles de Rai are often shrouded in mystery, and she happens to have her own agenda that differs from humans, vampires, and deviants alike, but her agenda might very well be known only to her. Gilles has a spiteful and sarcastic personality, and loves seeing others in dire situations due to her dyed-in-the-wool sadism.
Her distinguishing features are the artifact armor ‘Dole Gandis’ that she wears, which is similar to that of a medieval knight, and she wields a form of magic that was once believed to have been lost to history, which is the alchemy that is used to draw out and use the power of mystical artifacts.
In Vampire and Vampire REX, she serves as Ria File's subordinate, but happens to have an agenda of her own and later decides that she no longer has any need for her as her master when she arrives in Anhel's lair.
It has been revealed that in eXceed 3rd, Gilles de Rai is one of the seven members of The Cardinal Lords, married to the principal of the Belphegor Academy of Sorcery, and the mother of Giee, one of the participants in the Cardinal Lord Tournament and the Stage 3 boss of eXceed 3rd. How she was able to survive from the previous battle with Ria, and what have specifically happened to her during between the two interval of timeline is unknown.
- She is named after Gilles de Rais, a man who was Joan of Arc's right-hand man and lover and was claimed to be a mass murderer of children.