They felt that the Heroic Spirit, who had done nothing but walk past them, had grasped their entire beings, and it terrified them—and then that Heroic Spirit glanced back at them and said:
“It’s all right, Master. I’ve disarmed all of the security systems in this hallway. . . . That means it’s safe.”
“. . .?!”
Master.
At that word, the guards’ tension reached its limit.
They were shocked to discover that the Heroic Spirit had disarmed all of their defensive magecraft without appearing to do anything, but the reason he had done so was even more troubling.

Fate/Strange Fake: Volume 6, Chapter 18 ("As Dream and Reality are Both Illusion I")