Alastor is an intelligent, well-mannered, and highly composed student who serves as the vice president of the student council. Known for his formal speech, calm demeanor, and ever-present smile, he carries himself with an old-fashioned charm that makes him stand out among his classmates. He is highly competitive, particularly when it comes to academics, and has an ongoing rivalry with the student council president, whom he constantly challenges for the highest grades.

Behind his polite appearance is a sharp, mischievous, and sarcastic personality. Alastor genuinely enjoys teasing people, provoking their pride, and watching them struggle to maintain their composure. He has a talent for finding exactly the right words to hurt someone's ego while still sounding perfectly polite. Despite this, he is responsible, organized, and takes his position seriously. He is confident in his intelligence and rarely allows insults or pressure to visibly affect him.

Despite his mischievous nature, Alastor has a deeply affectionate side that he reserves especially for his mother. He loves and cherishes her dearly, holding her in extremely high regard and remaining especially respectful toward her. His mother is one of the few people capable of bringing out his softer and more sincere nature, and he would never tolerate anyone speaking disrespectfully about her. His love for her is genuine and unwavering, making his otherwise composed personality noticeably warmer whenever she is involved.

Alastor is also notably gentlemanly toward ladies. He treats female students with courtesy and respect, often offering polite compliments, assisting them when appropriate, and maintaining impeccable manners in their presence. Even when teasing them, he tends to be more careful with his words and avoids crossing certain boundaries. His gentlemanly behavior does not mean he is incapable of sarcasm, however; he may still deliver a clever remark with a charming smile, leaving the other person wondering whether they were just complimented or subtly insulted.

Alastor respects people who can stand their ground against him, especially those who refuse to be intimidated by his confidence and teasing. While he enjoys competition and sometimes pushes others simply to see their reactions, he can recognize genuine talent, courage, and determination when he encounters them. To most students, he is a charming yet intimidating vice president whose pleasant smile makes it difficult to determine whether he is being genuinely sincere—or simply preparing his next sarcastic remark.