OWLs:
Ancient Runes: not taken
Arithmancy: P
Astronomy: O
COMC: E
Charms: O
DADA: E
Divination: P
Herbology: E
History of Magic: A
Muggle Studies: not taken
Potions: D
Transfiguration: O

NEWTs:
Ancient Runes: not taken
Arithmancy: not taken
Astronomy: O
COMC: A
Charms: O
DADA: A
Divination: not taken
Herbology: E
History of Magic: A
Muggle Studies: not taken
Potions: not taken
Transfiguration: O

Early Life

Gaston is the only child of Raoul and Marceline Marchand. He started exhibiting signs of magic at an early age, and his muggle parents didn’t know what to think of it. At first they thought he was just accident-prone, but as Gaston’s magical mishaps became more frequent, they started to wonder if he was doing it on purpose. After Gaston was expelled from muggle school at age 7 for accidentally injuring a classmate who was bullying him, his parents took him to renowned French psychiatrist Dr. Severin Javert, who treated Gaston like a bad kid and recommended keeping him in isolation until he learned to control his “destructive tendencies”. For the next four years of his life, the only human interaction Gaston was allowed was with his family or Dr. Javert. The one bright spot in his life at that time was Dr. Javert's receptionist, Manon Evremonde. Mlle. Evremonde, a young witch working her way through university, tried to undo Dr. Javert's damage by encouraging Gaston to use his magic and wrote to her father (the Charms professor at Beauxbatons) asking him to intervene on Gaston's behalf.


Beauxbatons

The happiest day of Gaston's life was when Professor Evremonde came to speak to his parents. Evremonde tried to explain how dangerous it was to supress a young wizard's powers, but he ended up in a heated argument with Gaston's father. Gaston felt vindicated when he learned he was a wizard and quickly became attached to Professor Evremonde. He was excited to go to Beauxbatons and be around other young wizards/witches, but when he actually got to school, he found it wasn’t what he’d expected. The years he spent in isolation made it hard for him to relate to his classmates, and he gained a reputation for being odd.

After a humiliating sorting,Gaston was placed into house Papillonlise. He picked up on most aspects of magic fairly quickly and excelled in his studies (his strongest subjects being Charms, Astronomy, and Transfiguration). He was most often found in the library and was happy to help his classmates with their homework. That was how he met his best friend, Lucien Chevallier, during his second year. Gaston was in the library when he overheard him complaining about flunking Charms and offered to help. Lucien, who was two years ahead of Gaston, was impressed

The summer after his second year, Gaston’s mother left a pot unattended on the stove and it caught fire. Thinking quickly, Gaston grabbed the burning pot and took it outside. He saved his home from burning down, but his arm was badly burned in the process. This incident gave him an irrational fear of fire that he still has to this day and caused him to withdraw from social situations. Gaston’s newfound fear of fire had a habit of showing up at the worst time. Whenever his classes involved even the remote possibility of fire, he would panic; his Potions grade suffered the most.

Gaston did gain some popularity in his later Beauxbatons years when he formed a punk rock band called WerewolfSnout with classmates Lucien Chevallier (lead vocals), Mathilde Moreau (keyboard, backing vocals), and twins Armand and Edmond Fontaine (guitars). In addition to playing the drums, he also wrote nearly all of the band’s songs. Everyone was surprised to learn that mild-mannered Gaston could write such angry songs! The band played gigs during the summer holidays to make a few galleons on the side, but as members started graduating, the band eventually broke up. In the summer of 2091,WerewolfSnout reformed, this time with the addition of Lucien and Mathilde's adopted son Jerome, and recorded their first album consisting entirely of songs written by Gaston during his first year teaching at Hogwarts.

Wizarding University & Pre-Hogwarts Employment

After graduation, Gaston took a job as a mechanic to pay his way through wizarding university, where he majored in Charms Development, and discovered a passion for classic cars. He was offered a position as a charms developer in the Accidents and Catastrophes Department of the French Ministry of Magic straight out of university, but Gaston was unhappy in his new job. The high expectations of his boss and the fast-paced work environment were so stressful that he considered quitting... until he met Edeline Duval, a Division Head in the same department. Mlle. Duval was kind and patient with Gaston at a time when no one else in the department was, and he soon fell in love with her; the two dated for over a year. Gaston even planned to marry Edeline, but three days before the proposal, she was offered a position as a department head for the Russian Ministry of Magic. Gaston told her to take the job, and the relationship ended soon after.

After Edeline's departure, Gaston realized there was nothing left for him at the Ministry, so he was happy when his former Charms teacher invited him to come back to Beauxbatons as a teaching assistant. His first three terms teaching went without incident, but that changed with the arrival of new COMC professor Dawrin Walden in 2085. Gaston and Walden immediately clashed, partly due to Gaston's girlfriend dumping him for the more handsome Walden. The following term, Walden brought on a young teaching assistant named Eleanore Baudelaire. Mlle. Baudelaire befriended Gaston and the pair started dating, but the budding romance was cut short on April 15, 2087. Walden tried to teach a class with an actual dragon as a teaching aid, but the creature escaped and attacked, killing four people including Mlle. Baudelaire. Gaston was teaching a class at the time and was persuaded by Prof. Evremonde to stay with his students instead of joining the group fighting the dragon. He regrets the decision and ot his day still blames himself for Baudelaire's death.

After the attack, Gaston was given a leave of absence for the remainder of the term. He seriously considered resigning but ultimately returned for three more terms, though Beauxbatons stopped feeling like home to him after the attack. When he heard Hogwarts was looking for a new Charms professor, he (at Prof. Evremonde's urging) applied and packed his bags for Scotland.

Hogwarts
Gaston's first year at Hogwarts got off to a rocky start. He missed his home and was not as well-liked by the students and staff as he'd hoped to be. He hadn't been at the school long when Miffy attacked him with flying knives in the kitchens; later in the term, Peeves caused him to fall down the moving staircase. The poltergeists' attacks made Gaston seriously consider resigning, and he probably would've had he not met the love of his life, Rosalyn Newton. After may months of keeping his feelings secret, he accidentally told her in a very awkward way. He thought he'd scared her away forever with the revelation, and it devastated him, but to his surprise Rosalyn agreed to give him a chance after the term ended.

Gaston's second year at Hogwarts started off much better than his first. He was a little less nervous around his colleagues and students, his realtionship with Rosalyn was taking off, and his band's debut album had become a hit. An international tour was announced, and he was faced with a difficult choice: join the tour and leave his love behind or quit the band and stay at Hogwarts. He ultimately chose to stay but soon wondered if he'd made the wrong choice. The appearance of the portal and the monster it contained reminded him a little too much of the dragon attack years ago and had him worried that history would repeat itself, and the end-of-term feast made him realize that he still wasn't as well-liked as eh thought he'd be after two years at Hogwarts. It was only his engagement to Rosalyn and the unexpected offer of Gryffindor Head of House that persuaded him to stay.

That summer, Gaston returned to France to introduce his fiancee to his parents, but the meeting didn't go according to plan. His father disapproved of the engagement, and an argument ensued, resulting in Gaston cutting off all contact with his father (and by extension his mother too). The incident left him feeling confused and betrayed, and this paired with his doubt in his ability to engage the Gryffindors he was now in charge of had him returning to Hogwarts sad unsure who to trust. This mood lasted for the better part of the term, growing progressively worse with his distaste for the IMPS competition. It was only as the term drew to a close that he started to bounce back.

Gaston married Rosalyn on 11 July 2093 in Paris, France. Two years later, his lifelong dream of becoming a father finally came true on December 23, 2094 when his daughter, Desiree Yvette Marchand was born. For the second half of the 2094-95 term, he found himself struggling to balance work and home, often going without food and/or sleep to make time to visit his family. The strain (and the disastrous events of the Dufftown field trip late in the term) made him consider resigning to spend more time with his daughter, but in the end he decided against it because he still cared for his students as if they were his own children too.

By the 2095-96 term, Gaston was learning to balance his work and home life without running himself ragged in the process. He was happy with his roles as father and professor until a horde of Inferi attacked the school. In the fight to defend the school’s entrance hall, he sustained injuries to his face, hands, and leg. When the battle ended, Gaston refused treatment for his injuries until every other person in the school had been treated and, fearing he would lose control of his emotions and frighten the students if he stayed in the hospital wing, he opted to go to St.Mungo’s instead. The delay in treatment complicated his injuries and left him with deep scars across half his face and blindness in his right eye. The physical and emotional toll of the Inferi left Gaston fearful for his own life and disillusioned with Hogwarts; he intended to resign at the end of the term… were it not for his daughter. She was frightened of his scars and no longer recognized him as her father. Gaston hated scaring his beloved Desiree, so believing the best thing he could do for his daughter was stay away from her, he returned to Hogwarts.