Black Market

At first, Nial couldn't be bothered about the female butler. But when he began following her outside, he quickly noticed that her steps were nearly inaudible and that her presence was barely noticed by others.

Gianna had concealed her mana as well, which made it even difficult for Nial to gauge her rank.

Only if he were to reveal his Mana sense, and focus on penetrating her concealment would it be possible for him to find out her rank.

'Not bad' He thought, feeling slightly interested in the butler.

Nail's highly enhanced senses could still locate Gianna and follow her but every single motion of hers was several times quieter than that of a normal human, or Original.

'Assassin?' 

Quietly following Gianna, who didn't say a single word, they roamed through the market before buying some masks and a black robe.

Nial activated his armor's concealment function before returning to his train of thoughts.