"Because a king has no way of killing me." Scheherazade answered Astolfo's question directly.
"I see. So the legend has been sublimated."
An Heroic Spirit's Noble Phantasm, traits, weaknesses, and so on generally came from the legends of their lifetime. Take Achilles, for example—his heel was his fatal weakness. Once his True Name became known, an opponent's attacks would undoubtedly target his heel first.
Because of the tale of One Thousand and One Nights, Scheherazade had survived after making the king correct his past mistakes. The trait sublimated from that legend was that she could not be killed by a king.
As long as a Heroic Spirit possessed the King trait, killing her would be extremely difficult. Astolfo was not a king, but he was a prince. In theory, he could inherit the throne, so he too was affected by this trait.
"An interesting trait. What about me? I can give it a try."
Shen Fei had originally had no intention of attacking Scheherazade, but after learning of this trait, his curiosity was immediately piqued. He prepared to test it. As the emperor of Great Tang, he too belonged to the category of kings.
"Fireball." With that thought, Shen Fei condensed a blazing fireball roughly a meter in diameter in his right palm and fired it at Scheherazade.
"As expected." Watching his fireball get diverted by Scheherazade's magic circle, Shen Fei immediately understood that he too was affected by her trait of not being killed by a king.
Not being killed by a king did not mean Scheherazade could simply stand still and remain impossible for someone with the King trait to kill. Rather, when someone possessing the King trait attacked her, after she responded, it became very easy for her to evade the attack or divert it. Of course,