like a curse?
Place a sigil of ‘truth’ on the back of a small mirror. Flash it at the person’s image (in person, photos, etc) to bring the dread. 

Also, because it’s REALLY fun

Draw the same sigil on your palm, in some stark, startling color and style.

Lift your hand in a lazy greeting to  them with absolutely no expression on your face, being sure they saw the sigil. Then go wash it off. Be sure no cameras or other people saw you.

I’ve done it twice. They get the absolute heebie jeebies if you do it right, and if no one else saw and you washed it completely off…then they look even twice the fool. They can SAY you washed it, but people will start to doubt if you say-

 “I don’t know what she’s talking about. Maybe someone else told her they saw it, and she’s just….passing it on. You know she likes to do that sometimes.”

Then just shrug amicably and walk away.