C1463 Slaughterer of louvre

How could one describe the terror of this calamity cloud with words?

Raising his head, he could not see the sun in the sky at all. He could only feel the terrifying energy waves in the clouds, layer after layer, constantly emitting a strong killing intent.

"What exactly is this thing?"

"I don't know. I only know that the aura here is too terrifying, as if it is going to spill out at any moment