A Heroic Spirit's Noble Phantasm—especially one born from a legend as distinctive as this—could generally only be used by people who appeared in that legend.
Then there was Mordred's other Noble Phantasm.
The Helmet of Hidden Infidelity.
Her mother Morgan had given it to her along with the words, "You must never take it off."
Mordred's mother, Morgan, was King Arthur's sister and a powerful Witch—powerful enough to make King Arthur's father, King Uther, wary of her.
That was why this helmet—or rather, the armor it belonged to—had originally been a magical artifact created by Morgan.
It was meant to keep others from discovering Mordred's true identity before the time was right, and causing trouble as a result.
Because of that, the helmet could conceal some of Mordred's information.
It couldn't hide universal information like her parameters or Class Skills, but it could conceal crucial details such as her True Name, Noble Phantasms, and Unique Skills.
While in this state, she couldn't use "Clarent Blood Arthur."
Her parameters were only revealed when she removed the helmet while wearing the full set of helmet and armor.
In other words, if she removed the armor and carried no weapon, her parameters would remain concealed.
When the helmet's function was released, it split in two and merged with the armor.
The helmet and the armor, which her mother had also given her, had no other special effects, but they offered considerable defense against magecraft and external interference. Even when struck by an Anti-Army Noble Phantasm of B-Rank, the wearer would only be gravely injured. They could also provide some protection from toxins.
Though, in the end, it still hadn't been enough to stop Semiramis's poison.
In short, the girl had just fired her most powerful attack at Lin Yun and his group—and, most