Mysterious Adventurer
The Mysterious Adventurer is a person that can be found in the city of Kazas during the Serdian War. They claim to be the one who defeats the Dragon called Feyrbrand.
When visiting one of the buildings in Kazas, the Mysterious Adventurer will be present. They claim to smell the aura of a risky adventurer like Dart, offering to tell him a "great story" because the two are alike. The Mysterious Adventurer goes on to claim that they are the one who defeated Feyrbrand. Since Dart and company know they defeated that Dragon themselves, they just pause. The adventurer recognizes the distrust, going into a longer spiel to prove it.
The Mysterious Adventurer offers a look at a feather of Feyrbrand, but warns not to touch it as it's poisonous. Then, they introduce a great product to Dart. "A powerful drug that beats Dragons, the dragon beater!!" After offering one of their products for free, a Knight of Sandora enters the building to find whoever claimed they are responsible for defeating Feyrbrand. The knight moves toward Dart, but turns around noticing that the Mysterious Adventurer who tries to sneak out. As they are taken away, the adventurer admits to lying, but states that they're just doing business.