Vampires belong to the Order Evil camp, which is why Leon did not consider it a trap at first.
He always thought it was just a normal trade, albeit with a vampire, after all, his reputation was far worse than that of vampires—vampires should be the ones worried about him. It wasn't until he saw the maid who led him to the bathhouse leave with a meaningful smirk that he began to suspect something.
Leon carefully reviewed what had happened.
Right, he knew he was the Red Dragon, but in the eyes of others, he was just a Human, and to vampires, humans are just blood bags... He could almost be certain now that there was no mithril or refined gold at all, saying it was kept elsewhere—naturally, such important things should be kept as close as possible.