Oh my, Blood Magic is really such a rare thing!
It's so rare that this is the first time in Fanen's life that he's seen such a thing, even in the Magic Library of the Warrior Country, which was opened to him by Uffie, he hadn't encountered anything similar.
The Blood Clan, a race shrouded in mystery, is a race that most people first encounter in storybooks or in the ballads sung by bards. They are known by the more colloquial name "Vampire" and typically take on the role of the antagonist in stories.
Because the name Blood Clan is so well-known, it's so classic that when playwrights feature the Blood Clan in their stories, they don't need to provide additional introductions as the audience can fill in all the information about the Blood Clan themselves.
Due to their high appearance rate in various stories and ballads, many people have forgotten that in reality, the Blood Clan has not appeared for a long time.
