The boy glared and grit his back, displeased with Enkidu’s unpretentious response.
“Fine... This is a good time for a test.”, whispered the boy. In the next instant, he skillfully manipulated the high-speed energy circulating around him and started forming a whirlpool of raw magical energy with Enkidu at its center. “To test how big of a hole I can bite in the world now that I’m not with Flat.”
Magical energy manipulation bypassing chants, formulas or any kind of procedure.
This image alone would be enough for the Lords of the Clock Tower or the high-ranked engineers of the Atlas Institute to figure out what the boy was.
No matter how outlandish the answer may seem to them, nothing changes the fact that he exists.
Perhaps one of the Lords, a lecturer who observed Flat’s abnormalities for a long time, already knew about the creature for years.
“You want to compete against me? Heh, that would have been so enjoyable, had we met in a different place under different circumstances...”
“...”
Enkidu silent spread their arms opens at the same time the boy activated his magecraft.
The violent whirl of magical energy around them twisted space.
But almost at the same instant, countless chains sprouted from the floor Enkidu was stepping on, drawing a spiral spinning in the opposite direction as the space distortion to fill up all the space that would have been dislocated away.
With a bursting noise, the dense magical energy in the area dispersed.

Fate/Strange Fake, Volume 7; Chapter 21 (Beings Shaped In Man's Image)