Dünste is a male mage who appears during the First-Class Mage Exam arc in the city of Äußerst. He is a tall, thin man with a recessed hairline and long, dark hair that extends past his shoulders, complementing a neatly groomed and prominent mustache that makes him easily recognizable. His attire consists of long, black robes with two accented jacket panels over a light-colored hood and a white turtleneck shirt.

In terms of personality, Dünste is a reserved and pragmatic individual who speaks only when necessary and often defers to others within his party. He possesses a sharp analytical mind and demonstrates remarkable composure in dangerous situations, valuing cooperation and strategic thinking. While generally deferential, he shows a capacity for hesitation and concern when a companion's safety is at stake, revealing a sense of loyalty beneath his quiet exterior. His primary motivation throughout the story is to successfully navigate the rigorous trials of the First-Class Mage Exam and obtain the prestigious license.

Dünste's role in the narrative is that of a supporting yet pivotal participant in the examination. During the first stage of the exam, he is placed in the seventeenth party alongside two other mages, Edel and Blei. In this phase, he demonstrates his cooperative abilities by using a fire spell in an attempt to melt a lake frozen by another examinee, Lawine. His presence becomes more significant during the second stage of the exam, which takes place in a dungeon known as the Ruins of the King's Tomb. Here, the participants are hunted by magical clones, called Spiegel, that perfectly replicate the abilities of real mages. When his party is attacked by a clone of the proctor Sense, Edel is forced to retreat, and Blei stays behind to hold off the clone, buying Dünste precious time to flee. Injured and alone, he manages to reach a chamber where Frieren and other mages have gathered.

This moment defines his key relationships and his most important contribution. After being healed by the mage Methode, who possesses a holy scripture for simple healing magic, Dünste shares a critical piece of information with the group. He reveals that the clones are completely mindless, imitating the actions of their originals but possessing no will or heart of their own. This information, gleaned from his disqualified teammate Edel, is strategically vital as it frees the other mages from any moral hesitation about destroying the copies and allows them to formulate a more direct combat strategy. His relationships, therefore, are primarily forged through this context of tactical necessity, showing him as a reliable collaborator with his original teammates and a valuable informant to Frieren's group.

Dünste's development throughout the exam is subtle but present. He transitions from a mostly silent and background member of his party to a key survivor who carries forward essential intelligence. His brief moment of hesitation when told to flee from the Sense clone, hoping his comrade Blei managed to escape, is a small but telling sign of his internal conflict and loyalty. Ultimately, despite his crucial role and survival through the first two grueling stages, his journey concludes with a setback. In the third and final stage of the exam, presided over by the legendary great mage Serie, Dünste is deemed unworthy and fails to earn his First-Class Mage license.

Regarding notable abilities, Dünste is a competent offensive mage. He is shown casting an unnamed fire spell powerful enough to be used against a large frozen surface. He is also proficient in Zoltraak, a standard yet highly effective offensive magic that fires concentrated mana blasts, which he employs in combat against a clone of the mage Richter. While not presented as an exceptionally powerful mage compared to the main cast, his true strength lies in his cool-headed analysis, will to survive, and ability to make decisive contributions through information rather than raw magical power.