Demiurge Hellfire soul manip

“[Hellfire Wall].”
A wave of heat crashed into her back. Evileye could not believe it, and hurriedly turned back to look.
There was a foom, and then it seemed as though the night itself had caught fire. Unnatural black flames surged into the sky.
The fleeing Gagaran and Tia were enveloped by the black fire. Their limbs twitched like puppets, and they fell to the ground like a bunch of rubbish. When the fire had vanished like it had never been, the two of them remained motionless. Evileye fought the impulse to rush to their side. She could hardly believe it, but she had no choice but to do so. Evileye knew those had been fatal injuries. With just a single blow, the comrades with whom she had shared her joy and sorrow had lost their lives.

- Overlord; Vol 6; Chapter 9

[...]

She’d thought they would have been burned beyond recognition, but it
seemed that the devil’s flames had only burned the soul rather than the flesh.
The corpses were immaculate. After closing their eyes and crossing their arms
over their chests, Evileye withdrew a Shroud of Sleep from her pack, and began
by wrapping up Tia.

Overlord; Vol 6; Chapter 10

[...]

“It is as you have surmised. The fire-type damage was strengthened by a
special ability.”
On closer observation, the flames wreathing Jaldabaoth had a blackish tinge
to them.
“Hellfire, is it?!”
“Just so. Even a being protected with fire immunity will not escape unscathed,
don’t you think?”

- Overlord; Vol 6; Chapter 11