Megumin's most notorious trait is her obsession for Explosion Magic. After being saved by a mysterious stranger using that spell, Megumin instantly fell in love with the Explosion Magic's unparalleled destructive power, dedicating years studying and saving points in order to master the spell, while ignoring its many demerits. After learning it, Megumin started to come up with excuses to use Explosion Magic every day, recklessly using the spell even when she knows it will cause problems for her and her party. Megumin also doesn't accept any other type of explosion, like Kazuma's tinymites.

Like almost all Crimson Demons, Megumin has a chuunibyou personality, often making speeches using old Japanese dialect and striking cringe-worthy poses. However, her act can drop easily. She is also an attention seeker and has delusions of grandeur (calling herself "the foremost arch wizard and wielder of Explosion Magic" and boasting about her genius and talent, as well as fantasizing about becoming the next Devil King), alongside a taste for strange names, "cool" stuff and destructive hobbies. Although Megumin also enjoys cute stuff, she doesn't admit it in order to keep her "cool" poise.