Finn is a character from the anime and manga series Wistoria: Wand and Sword. He is a mysterious individual who first appears before Will Serfort following the climax of a deadly dungeon expedition. Finn is a member of the Finn Tribe, also known as the Light Clan, a race of small, dwarf-like people who are characterized by their inability to use magic. Unlike most races in the world of Wistoria, such as Elves who are renowned for their magical prowess, the Finn Tribe is often looked down upon for their lack of magical ability, placing them in a similar social position to the protagonist, Will. Despite his childlike and diminutive appearance, which resembles that of a seven-year-old boy, there are hints that Finn may be much older, potentially decades or even centuries old. This is suggested by his deep knowledge and the nature of his work, even though his physical form does not appear to age.

In terms of personality, Finn is portrayed as helpful, knowledgeable, and somewhat secretive. He possesses a calm and serious demeanor, especially when discussing matters related to dungeons or the history of swords. One notable aspect of his character is his aversion to the name "Inves," which is another title that has been used for him. He makes it clear that he dislikes being called by that name and prefers to be addressed by his chosen name, Finn, or in relation to his tribe.

Finn’s primary role in the story is that of a guide and a mentor, specifically concerning matters of the sword. While he is entirely unable to cast spells, he possesses an exceptionally deep knowledge of dungeons. This expertise makes him an indispensable asset, even to the most powerful mages, including the elite Magia Vander who are known as the Five Supreme Wands, for navigating the dangerous depths of the dungeons. He takes a particular interest in Will Serfort, whom he refers to as the Sword. Finn appears to have a singular duty to guide and support individuals who are connected to the sword in a world dominated by magic. He decides to take a personal interest in Will's journey after learning of the boy's ambition to reach the top of the magical world.

Finn's relationships with other key characters are defined by his ancient duty and mysterious origins. He has a significant connection to the Witch Queen Mercedes, with whom he seems to have entered into a contract or some form of pact, though the full nature of this agreement remains unclear. He also has dealings with the head of the Rigarden Mage Academy, Headmaster Caldron, to whom he reports concerning disturbing activities and powerful weapons emerging from the dungeon. However, his most important relationship is with Will Serfort. Upon witnessing Will’s ability to absorb magical attacks into his sword, a power that blends wand and sword, Finn recognizes him as a crucial piece in a larger puzzle and takes on the role of a guide, aiming to teach Will more about his own potential. This guidance is not solely academic; Finn has demonstrated the ability to appear before Will during critical, life-threatening moments to offer essential advice and reveal hidden truths about his unique power.

As the narrative develops, Finn becomes instrumental in explaining the nature of Will’s power. While other characters struggle to understand why Will, a magicless boy, can fight on equal footing with powerful mages, Finn provides the answer. He reveals that Will does possess a form of magic that is unique to him, one that revolves around the sword. This revelation positions Finn as a key figure in unlocking Will’s potential and understanding the lore of the world, particularly regarding the mage slayer swords that are part of hidden experiments taking place within the dungeon. His introduction marks a major turning point, shifting the story from a simple underdog narrative to a larger mystery involving the history of the world and the true power of the sword.