This is what is called an Evil Eye magic spell.

Magic only works on people if they don't know they have a spell on them.

It doesn't matter if the occult magic is true/real. What matters is these Satanists believe it.

And they are acting under the assumption the spells are working. That makes them dangerous, regardless of its actual effectiveness.

https://www.sacred-texts.com/evil/tee/index.htm