Jean Colbert is a professor at the Tristain Academy of Magic, where he teaches history and pursues a deep fascination with the science and technology of other worlds. A square-class fire mage with an affinity for flame, he seldom uses his magic openly.

He was once known as "Flame Snake," a commander of mage troops who led a mission to destroy a village thought to be plague-ridden. After discovering the village was not infected, he rescued a young girl named Agnès. This revelation transformed his perspective, turning him toward pacifism and filling him with regret for his past violence.

Colbert supervises the academy’s familiar summoning ritual and was present when Louise summoned Saito Hiraga. He took immediate notice of the runes on Saito’s hand, identifying them as those of the legendary Gandálfr. On Headmaster Osmond’s instruction, he kept this discovery secret due to its ties to the Void element.

During the Fouquet incident, Colbert aided in securing the Vault and later discussed the origins of the Staff of Destruction with Saito and Osmond. His curiosity about Saito’s world drove him to develop gasoline, which powered an airplane. He expressed admiration upon learning that modern Japan had known periods of peace, which reinforced his anti-war beliefs.

With help from Tabitha and Kirche, Colbert staged his own death to protect Agnès, convincingly simulating his demise before later reappearing to support Saito and Louise against adversaries such as Sheffield.

He has no living relatives, and prior to the revelation of his faked death, arrangements had been made for his remains to be buried on Kirche’s lands.

Colbert is widely regarded as a calm, kind, and understanding figure, often approached by students for guidance. He maintains a supportive, mentoring relationship with Saito.