Erhardt has long, wavy blonde hair and green eyes. He wears a knight uniform similar to Olberic's, with a black tunic over a red shirt, white gloves, and gold-colored shoulder guards and bracers.
21 years prior to the start of Octopath Traveler, Erhardt's hometown of Grynd was burned to the ground. His people believed King Alfred would come to their aid, but he did not. Erhardt was filled with hatred and swore to make the king pay for his actions or lack thereof. He was later picked up by Werner's band of sellswords, the Black Brotherhood, who sought the destruction of Hornburg. Werner had Erhardt appointed as a knight of the king's own guard and manipulated him into committing regicide.
Erhardt had hoped the death of the king would free him of his emotional turmoil, but it only filled him with emptiness. He expresses remorse for dedicating his life to vengeance, having realized that he valued the memories of his time as a knight more than those of his lost home. After the Black Brotherhood disbanded, Erhardt began wandering. He ended up in Wellspring and is viewed as a local hero for protecting the people from Lizardmen.
- "The lizardmen have retreated, but there is no end to our problems." —Speaking to Erhardt
- "Lead on, Sister." —Guide
- "I feel compelled to follow." —Allure
- "Call upon me at any time." —Part Ways (Ophilia)
- "Finally, I'm free." —Part Ways (Primrose)
- "Make good use of it." —Purchase
- "Come at me, Olberic!" —Challenge
- "I see, this was just training exercise." —Provoke
- "U-ugh..." —Defeated
- "Begone, eyesore!" —Failure
- According to travel banter, he is a heavy drinker, enough to push Olberic to his tipping point. Cyrus is the only other person known to have accomplished this feat.