It was crawling along the sides of buildings like a giant spider straight out of a movie. And yet, Haruri could sense nothing like magical energy from it. It did not seem to make noise, either, and there was no sign of panic on the part of the people inside the buildings it crawled on.
“Don’t worry,” Filia, swelling with pride, told a doubtful Haruri. “His presence and form are completely isolated. I’ve made it so that only you and I can see him.”
Filia spoke off-handedly, but Haruri, who understood what a feat that was, felt a renewed fear of the being in front of her. A full day had passed since their meeting, and Haruri still had no idea of her true identity or objective

Fate/Strange Fake: Volume 4, Chapter 10 ("Day 2")