The Key and Lock

Although Vaan's mocking angered Lady Nurla, she still possessed her reasoning. As such, she was alarmed by the invisible barrier that protected him. It had appeared without warning and seemed nigh unbreakable.

Where did such a strong barrier come from?

Lady Nurla didn't believe such a powerful barrier could have been produced with Vaan's cultivation. As such, it had to come from somewhere else.

A treasure?

In order to verify her suspicion, Lady Nurla threw herself at Vaan again, attacking the invisible barrier with wings, tail, legs, and arms. She utilized all her limbs to strike different spots on the spherical barrier as if to find its weak point.

However, no matter where she struck, the invisible barrier remained firm and unshakeable.

Nevertheless, the glimmers of light from the tiny temple that floated around Vaan made Lady Nurla realize where the barrier power came from. Indeed, the barrier power came from a treasure.