Elhart, also known as Erhard, is the seasoned blacksmith who runs a weapon shop in Melromarc's Castle Town. He is a middle-aged or older man with a well-built frame, etched with old scars on his face and arms from his past as an adventurer. His distinctive appearance includes a shaved head, an Amish-style beard without a mustache, brown or dark eyes, and partially tanned skin. He is typically seen wearing a practical outfit consisting of an off-white undershirt, a beige forger's apron, black gloves, dark brown pants, and brown-beige boots.

Elhart is openly cheerful and compassionate, with a strong sense of justice. He rejects the dominant religious prejudices of Melromarc that condemn the Shield Hero and discriminate against demi-humans, instead choosing to judge people solely by their character. He is notably perceptive, able to tell when someone is lying, which was crucial in his early assessment of Naofumi Iwatani. Despite initially believing the false charges against the Shield Hero, he quickly realized the truth and became one of Naofumi's first and most steadfast allies. His motivation stems from a personal code of fairness and a practical understanding that a person's nature is not dictated by the roles forced upon them. He supports Naofumi not out of a grand political statement but because he sees a young man in need of honest help and refuses to be swayed by the kingdom's propaganda.

In the story, Elhart plays a vital role as Naofumi’s primary supplier of weapons, armor, and accessories. Naofumi, who refers to him affectionately as the weapon shop old man, trusts him immensely, second only to Raphtalia. Elhart provides crucial early support by giving Naofumi supplies when he was penniless and despised, crafting custom-made barbarian armor, and creating shields and weapons from rare materials that Naofumi brings him. He also gifts Naofumi a rusty sword, which allows the Shield Hero to unlock a new shield. Beyond crafting, Elhart’s past as an adventurer makes him a capable combatant, and he serves as a mentor, teaching Raphtalia and others swordsmanship. His shop becomes a safe haven for Naofumi's party, a place where they can plan and prepare without judgment.

His key relationships are defined by deep mutual trust. With Naofumi, Elhart maintains discretion about the nation's cruel views to spare him pain, and he consistently offers fair deals, sometimes even adding extra items for free. He is a fatherly figure to Raphtalia, recognizing her growth and unspoken feelings, and he equips her for battle from the moment Naofumi first buys her. He also has a significant connection to the enslaved blacksmith Tollynemiya, revealed to be a fellow apprentice under the same master. This past relationship ties into Elhart's own development; his journey as a blacksmith began when he was an adventurer traveling the world. After seeing an incredible weapon, he abandoned his adventuring life to apprentice under the master who made it, alongside Tolly. Later, during the events in Q'ten Lo, Elhart reunites with this master and confronts him over past debts and incomplete training, forcing the master to provide advanced lessons that further hone Elhart's already considerable skills.

Elhart possesses notable abilities that make him renowned as one of the finest blacksmiths in Melromarc. Unlike specialists, he is capable of creating a wide variety of weapons, armor, and accessories, and he can work with notoriously difficult materials, including those from Guardian Beasts. As a retired, class-upped adventurer, he retains a high level of strength and combat proficiency. His broad perspective on weapon making, a lesson from his master, allows him to craft effective gear from any material provided, making him an indispensable asset to Naofumi and the other heroes.