The sorcerer Gilles de Rais used dark magic to create special concoctions that could turn any human into a demon. He used this concoction on himself to turn into a demon known as Martinet and consumed it again to revert back to normal.
When used on other people, they became demons who were completely loyal to Gilles' cause and lacked their original kind hearts, disregarding former friends and allies upon transformation. They essentially became mind-controlled without needing to be ordered around.
Gilles used this concoction to turn Jeanne d'Arc and Favaro Leone into demons. The former so she could slay the three gods maintaining Bahamut's seal and the latter so he could prevent his friends rescuing Amira.
Both of them were cured by Rita, who had successfully created antidotes. Rita also noted that prolonged consumption could lead the consumer's body to morph between forms on its own, as seen with Gilles.
- It is never explained why Jeanne and Amira's appearances changed completely upon transformation yet only Favaro's eyes changed when Favaro transformed.
|Objects||Alessand's dagger • Amira's compass • Amira's pendant • Bahamut's Talon • Barossa's dagger • Black Bible • Bounty Hunter's Bracer • Charioce XVII's bracelet • Demon Key • Dromos • El's ocarina • El's toy • Favaro's crossbow • God Key • Golem • Green Stone • Hoverboard • Maltet • Marginal Golem • Martinet's concoction • Nina's whip • Précieuse • Rita's antidotes • Rita's staff • Smoke Bomb • Transcendence Key|