Serge Durandal is a famous wizard that attended Gedonelune Academy before he went missing six years prior to the beginning of the game. He is mentioned to be a talented animal tamer and is the idol of Liz Hart. He serves as prefect alongside Klaus Goldstein, eventually ending up as his roomie.
As a child, Serge lived with his grandmother, who owned a magical sweets shop, and she instilled in him early a love of magic. Later, Serge attended Gedonelune Royal Magic Academy as a student, where he became notable for his talents in magic. During his time at the academy, he befriended Randy March and Klaus Goldstein, with the former being his best friend and buddy.
Serge and Randy were very ambitious wizards and often performed magical experiments together. One of those included finding an easier way to summon powerful magical creatures, such as unicorns. One day, however, the summoning experiment went terribly wrong, as the pair messed up on their summoning circle and accidentally summoned a basilisk, which petrified Randy, turning him to stone, rendering him in a state akin to death.
After the basilisk incident, Serge and Klaus were both devastated by Randy's death, and heavily strained the relationship between the two, in which Klaus started calling Serge "the 'murderer'". Serge also went back to the place where Randy had been petrified and planted carem seeds, as they were Randy's favorite flower.
Serge left the academy shortly after, blaming himself for Randy's accident, and traveled the world in hopes of finding a way to revive Randy, and even took up the name "Randy March" because he did not want to be the "Murderer Serge Durandal" and even went as far to blot his own name from the books at the academy.
During his travels, he eventually went to Hinomoto and befriended Azusa Kuze, who would later become a transfer student at the academy, and Serge's original roommate.
Serge is very optimistic, childish, carefree, silly, and even described by some as eccentric. He almost always has a smile on his face and is very open about his emotions, even to the point where he asks Liz Hart to be his girlfriend. He has no trouble saying things that would be considered "inappropriate." He is also very trusting of his friends, as he doubted the possibility of Azusa using dark magic when he was accused of such.
Despite his child-like tendencies, he has an immense love for all magic and is a firm believer that there is no right or wrong in magic. He especially extends this belief to the Liz Hart, even after she messed up a spell. Serge is also very knowledgeable in magic and loves to experiment with it, often on his familiar, Taffy. Serge is also very knowledgeable about magic in general and magical creatures as well.
Serge also has a more sadistic and manipulative side to him when he is conducting experiments, although he really only shows that side of him to Taffy.