Servant bonds... they left a mark, a sort of imprint on the servant's body and by what she had heard the type of mark that would appear varies accordingly to which master one servant is forced to be bound to.
Though truthfully, rather than acting as a mark, it was just an invincible chain on one's body, marked on the skin in a form of showing one's possession, a rather twisted hobby that Seraphs enjoys. It's not uncommon for Seraphess in the higher caste would often buy a slave just for fun to see what kind of mark would appear on their servant's body, as if it was fashion.
Evangeline had heard it a little during the time she visited houses to sell her woven delicates but now seeing it up close, it felt more like a brand, a brand that would never leave one's body no matter what one's do.
